<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019c53e8-8b56-7759-95a2-c7bd71b202ce,g:d552457c-3248-4c12-934b-c7c4108a96b5-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="https://xbrl.org/2023/arcrole/summation-item" xlink:type="simple" xlink:href="https://www.xbrl.org/2023/calculation-1.1.xsd#summation-item"/>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/ConsolidatedBalanceSheets" xlink:type="simple" xlink:href="arwr-20260331.xsd#ConsolidatedBalanceSheets"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/ConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019c53e8-8c90-71fc-afab-f7bdccb1bd04" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_019c53e8-8c90-7c51-a503-f8cce609718b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019c53e8-8c90-71fc-afab-f7bdccb1bd04" xlink:to="loc_us-gaap_AccountsPayableCurrent_019c53e8-8c90-7c51-a503-f8cce609718b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_019c53e8-8c90-773d-8c38-db6c45339a7f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019c53e8-8c90-71fc-afab-f7bdccb1bd04" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_019c53e8-8c90-773d-8c38-db6c45339a7f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019c53e8-8c90-7940-902e-d72b5e5aadee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019c53e8-8c90-71fc-afab-f7bdccb1bd04" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019c53e8-8c90-7940-902e-d72b5e5aadee" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_019c53e8-8c90-7ff7-9644-ed9f1caa8fb5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019c53e8-8c90-71fc-afab-f7bdccb1bd04" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_019c53e8-8c90-7ff7-9644-ed9f1caa8fb5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LinesOfCreditCurrent_019c53e8-8c90-774f-bafd-fcc752ee935a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LinesOfCreditCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019c53e8-8c90-71fc-afab-f7bdccb1bd04" xlink:to="loc_us-gaap_LinesOfCreditCurrent_019c53e8-8c90-774f-bafd-fcc752ee935a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_019c53e8-8c90-7f00-9f14-3427e3df44a7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019c53e8-8c90-71fc-afab-f7bdccb1bd04" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_019c53e8-8c90-7f00-9f14-3427e3df44a7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019c53e8-8c90-75b3-b974-0d70914f168b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019c53e8-8c90-71fc-afab-f7bdccb1bd04" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019c53e8-8c90-75b3-b974-0d70914f168b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019c53e8-8c90-7ef2-b25f-640e5509610b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019c53e8-8c90-70ed-8599-22fedab79992" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019c53e8-8c90-7ef2-b25f-640e5509610b" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019c53e8-8c90-70ed-8599-22fedab79992" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019c53e8-8c90-7ad1-8889-a2313cd4627f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019c53e8-8c90-7ef2-b25f-640e5509610b" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019c53e8-8c90-7ad1-8889-a2313cd4627f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestments_019c53e8-8c90-7bba-983d-7efde7ed82e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermInvestments"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019c53e8-8c90-7ef2-b25f-640e5509610b" xlink:to="loc_us-gaap_ShortTermInvestments_019c53e8-8c90-7bba-983d-7efde7ed82e0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseCurrent_019c53e8-8c90-73fe-a4b3-3d04c6377b2b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019c53e8-8c90-7ef2-b25f-640e5509610b" xlink:to="loc_us-gaap_PrepaidExpenseCurrent_019c53e8-8c90-73fe-a4b3-3d04c6377b2b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent_019c53e8-8c90-7f86-a040-bc111ecac2fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019c53e8-8c90-7ef2-b25f-640e5509610b" xlink:to="loc_us-gaap_OtherAssetsCurrent_019c53e8-8c90-7f86-a040-bc111ecac2fa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019c53e8-8c90-7e95-b59b-1c357d00f8b6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019c53e8-8c90-730f-9c00-847f392cee59" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019c53e8-8c90-7e95-b59b-1c357d00f8b6" xlink:to="loc_us-gaap_AssetsCurrent_019c53e8-8c90-730f-9c00-847f392cee59" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019c53e8-8c90-7ddf-af9b-e8a93eafb944" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019c53e8-8c90-7e95-b59b-1c357d00f8b6" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019c53e8-8c90-7ddf-af9b-e8a93eafb944" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8c90-7455-904f-e46fdf5f785f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019c53e8-8c90-7e95-b59b-1c357d00f8b6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8c90-7455-904f-e46fdf5f785f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_019c53e8-8c90-70ca-8f35-352fb968d46a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019c53e8-8c90-7e95-b59b-1c357d00f8b6" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_019c53e8-8c90-70ca-8f35-352fb968d46a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_019c53e8-8c90-7f54-bd1e-fa4263bf1821" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019c53e8-8c90-7e95-b59b-1c357d00f8b6" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_019c53e8-8c90-7f54-bd1e-fa4263bf1821" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019c53e8-8c90-77ee-80a5-80c37c81ffa6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019c53e8-8c90-78ed-87e1-80053a204820" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019c53e8-8c90-77ee-80a5-80c37c81ffa6" xlink:to="loc_us-gaap_LiabilitiesCurrent_019c53e8-8c90-78ed-87e1-80053a204820" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesNoncurrent_019c53e8-8c90-71f1-a366-5dd9eab14d17" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019c53e8-8c90-77ee-80a5-80c37c81ffa6" xlink:to="loc_us-gaap_LiabilitiesNoncurrent_019c53e8-8c90-71f1-a366-5dd9eab14d17" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_019c53e8-8c90-789e-acd8-423c26893f51" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019c53e8-8c90-77ee-80a5-80c37c81ffa6" xlink:to="loc_us-gaap_CommitmentsAndContingencies_019c53e8-8c90-789e-acd8-423c26893f51" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019c53e8-8c90-705b-9239-2442563c6a6f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019c53e8-8c90-77ee-80a5-80c37c81ffa6" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019c53e8-8c90-705b-9239-2442563c6a6f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019c53e8-8c90-7d5b-996a-75a2d217a90d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019c53e8-8c90-74db-bdd7-a2a7005a1128" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019c53e8-8c90-7d5b-996a-75a2d217a90d" xlink:to="loc_us-gaap_StockholdersEquity_019c53e8-8c90-74db-bdd7-a2a7005a1128" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_019c53e8-8c90-7b37-85f6-fcdf2a935a8c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterest"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019c53e8-8c90-7d5b-996a-75a2d217a90d" xlink:to="loc_us-gaap_MinorityInterest_019c53e8-8c90-7b37-85f6-fcdf2a935a8c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesNoncurrent_019c53e8-8c90-7e6e-b74c-52e9bd12b624" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesNoncurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019c53e8-8c90-7c54-a5ab-10249600da9e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesNoncurrent_019c53e8-8c90-7e6e-b74c-52e9bd12b624" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019c53e8-8c90-7c54-a5ab-10249600da9e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_019c53e8-8c90-76d9-9add-65f7f73197a5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesNoncurrent_019c53e8-8c90-7e6e-b74c-52e9bd12b624" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_019c53e8-8c90-76d9-9add-65f7f73197a5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_RoyaltiesLiabilityNoncurrent_019c53e8-8c90-7f3c-8360-088f8e07b7e5" xlink:href="arwr-20260331.xsd#arwr_RoyaltiesLiabilityNoncurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesNoncurrent_019c53e8-8c90-7e6e-b74c-52e9bd12b624" xlink:to="loc_arwr_RoyaltiesLiabilityNoncurrent_019c53e8-8c90-7f3c-8360-088f8e07b7e5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermLineOfCredit_019c53e8-8c90-7eaf-ac68-532f549a20c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermLineOfCredit"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesNoncurrent_019c53e8-8c90-7e6e-b74c-52e9bd12b624" xlink:to="loc_us-gaap_LongTermLineOfCredit_019c53e8-8c90-7eaf-ac68-532f549a20c0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtNoncurrent_019ce576-b61b-7fdc-9984-e4c3a3ad1d06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertibleDebtNoncurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesNoncurrent_019c53e8-8c90-7e6e-b74c-52e9bd12b624" xlink:to="loc_us-gaap_ConvertibleDebtNoncurrent_019ce576-b61b-7fdc-9984-e4c3a3ad1d06" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019c53e8-8c90-702c-8d0e-2a1ebe12aba1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019c53e8-8c90-71f4-aad4-81eef9893a9b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019c53e8-8c90-702c-8d0e-2a1ebe12aba1" xlink:to="loc_us-gaap_CommonStockValue_019c53e8-8c90-71f4-aad4-81eef9893a9b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_019c53e8-8c90-7585-ac9a-eb1b1f595c7b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019c53e8-8c90-702c-8d0e-2a1ebe12aba1" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_019c53e8-8c90-7585-ac9a-eb1b1f595c7b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019c53e8-8c90-7770-ac10-ca0c3837d029" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019c53e8-8c90-702c-8d0e-2a1ebe12aba1" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019c53e8-8c90-7770-ac10-ca0c3837d029" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019c53e8-8c90-74fe-99de-28be0705ed56" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019c53e8-8c90-702c-8d0e-2a1ebe12aba1" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019c53e8-8c90-74fe-99de-28be0705ed56" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonValue_019c53e8-8c90-773b-865e-2133aaf5bd5f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonValue"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019c53e8-8c90-702c-8d0e-2a1ebe12aba1" xlink:to="loc_us-gaap_TreasuryStockCommonValue_019c53e8-8c90-773b-865e-2133aaf5bd5f" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/ConsolidatedStatementsofOperationsandComprehensiveLossIncome" xlink:type="simple" xlink:href="arwr-20260331.xsd#ConsolidatedStatementsofOperationsandComprehensiveLossIncome"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/ConsolidatedStatementsofOperationsandComprehensiveLossIncome" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019c53e8-8c90-7fb2-8a7c-f8b46c14ba4b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019c53e8-8c90-7e1a-94ee-79066df8eff5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019c53e8-8c90-7fb2-8a7c-f8b46c14ba4b" xlink:to="loc_us-gaap_OperatingIncomeLoss_019c53e8-8c90-7e1a-94ee-79066df8eff5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019c53e8-8c90-71d8-b235-fcd82fce6d6f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019c53e8-8c90-7fb2-8a7c-f8b46c14ba4b" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019c53e8-8c90-71d8-b235-fcd82fce6d6f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_019d433a-4cc4-703e-b771-41689a34a4d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019d433a-4cc4-73c4-afa3-8cd43608e49e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019d433a-4cc4-703e-b771-41689a34a4d9" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019d433a-4cc4-73c4-afa3-8cd43608e49e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_019d433a-4cc4-7259-b751-9749b0640194" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019d433a-4cc4-703e-b771-41689a34a4d9" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_019d433a-4cc4-7259-b751-9749b0640194" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019c53e8-8c90-7d20-9faf-3b32359e5ae3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019c53e8-8c90-7986-8531-4d0a1eb28854" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019c53e8-8c90-7d20-9faf-3b32359e5ae3" xlink:to="loc_us-gaap_ProfitLoss_019c53e8-8c90-7986-8531-4d0a1eb28854" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019c53e8-8c90-7cef-b2a1-1dd1f836ea34" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019c53e8-8c90-7d20-9faf-3b32359e5ae3" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019c53e8-8c90-7cef-b2a1-1dd1f836ea34" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019c53e8-8c90-7a59-852a-98364019cefc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpenses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_019c53e8-8c90-71af-b51b-d2d750935ff3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_019c53e8-8c90-7a59-852a-98364019cefc" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_019c53e8-8c90-71af-b51b-d2d750935ff3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019c53e8-8c90-7a83-9fb8-3b3d7ec6d87d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_019c53e8-8c90-7a59-852a-98364019cefc" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019c53e8-8c90-7a83-9fb8-3b3d7ec6d87d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019d9c1e-a4f2-7ba6-8e3f-5ff837f15aec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterestAndDividend_019d9c1e-a4f2-7af2-b4e8-817263ed149a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIncomeInterestAndDividend"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019d9c1e-a4f2-7ba6-8e3f-5ff837f15aec" xlink:to="loc_us-gaap_InvestmentIncomeInterestAndDividend_019d9c1e-a4f2-7af2-b4e8-817263ed149a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019d9c1e-a4f2-74d0-abf7-0de4bd4b3bd8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019d9c1e-a4f2-7ba6-8e3f-5ff837f15aec" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019d9c1e-a4f2-74d0-abf7-0de4bd4b3bd8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019d9c1e-a4f2-7229-a265-ae0fc1c75d64" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019d9c1e-a4f2-7ba6-8e3f-5ff837f15aec" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019d9c1e-a4f2-7229-a265-ae0fc1c75d64" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets1_019d9c1e-a4f2-7250-b638-61eb17b89c79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnDispositionOfAssets1"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019d9c1e-a4f2-7ba6-8e3f-5ff837f15aec" xlink:to="loc_us-gaap_GainLossOnDispositionOfAssets1_019d9c1e-a4f2-7250-b638-61eb17b89c79" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019dba88-1647-7cac-a4ac-7fabff305e3f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019d9c1e-a4f2-7ba6-8e3f-5ff837f15aec" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019dba88-1647-7cac-a4ac-7fabff305e3f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019c53e8-8c90-7285-8f84-617869abe36e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019c53e8-8c90-780a-85d6-070b8fb97bb4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ProfitLoss_019c53e8-8c90-7285-8f84-617869abe36e" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019c53e8-8c90-780a-85d6-070b8fb97bb4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019c53e8-8c90-7c76-bacf-bcd6fb8e8dfd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ProfitLoss_019c53e8-8c90-7285-8f84-617869abe36e" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019c53e8-8c90-7c76-bacf-bcd6fb8e8dfd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019d4338-e486-7a35-b152-b8c8b93d3f4c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_019d4338-e486-73a8-a07f-9cf5fe522b63" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019d4338-e486-7a35-b152-b8c8b93d3f4c" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_019d4338-e486-73a8-a07f-9cf5fe522b63" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_019d4338-e486-7caf-8b3e-2d10f7379eca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019d4338-e486-7a35-b152-b8c8b93d3f4c" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_019d4338-e486-7caf-8b3e-2d10f7379eca" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019c53e8-8c90-7e22-a5c6-f97ab84ea5f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019c53e8-8c90-78b7-9512-2b987c7c361f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_019c53e8-8c90-7e22-a5c6-f97ab84ea5f3" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019c53e8-8c90-78b7-9512-2b987c7c361f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019c53e8-8c90-7188-8e94-42ba61f721f7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpenses"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_019c53e8-8c90-7e22-a5c6-f97ab84ea5f3" xlink:to="loc_us-gaap_OperatingExpenses_019c53e8-8c90-7188-8e94-42ba61f721f7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019c53e8-8c90-7276-9292-824208ee2c28" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019c53e8-8c90-75b7-b497-0e474a6bf333" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019c53e8-8c90-7276-9292-824208ee2c28" xlink:to="loc_us-gaap_ProfitLoss_019c53e8-8c90-75b7-b497-0e474a6bf333" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019c53e8-8c90-7720-9051-66a3dbeb349b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019c53e8-8c90-7276-9292-824208ee2c28" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019c53e8-8c90-7720-9051-66a3dbeb349b" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/ConsolidatedStatementsofCashFlows" xlink:type="simple" xlink:href="arwr-20260331.xsd#ConsolidatedStatementsofCashFlows"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/ConsolidatedStatementsofCashFlows" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019c53e8-8c90-75bd-b1e4-ca84342d94d6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_ProfitLoss_019c53e8-8c90-75bd-b1e4-ca84342d94d6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_019c53e8-8c90-7e4d-833c-5b77c85308b5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_ShareBasedCompensation_019c53e8-8c90-7e4d-833c-5b77c85308b5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_019c53e8-8c90-7eaa-96da-679cd3732021" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_DepreciationAndAmortization_019c53e8-8c90-7eaa-96da-679cd3732021" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeNetAmortizationOfDiscountAndPremium_019c53e8-8c90-741d-9117-9a6c14623df4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIncomeNetAmortizationOfDiscountAndPremium"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_InvestmentIncomeNetAmortizationOfDiscountAndPremium_019c53e8-8c90-741d-9117-9a6c14623df4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_019c53e8-8c90-774b-a5e5-c25ef0165562" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_019c53e8-8c90-774b-a5e5-c25ef0165562" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_019c53e8-8c90-7c2a-a0b6-f672d2e39574" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealizedInvestmentGainsLosses"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_RealizedInvestmentGainsLosses_019c53e8-8c90-7c2a-a0b6-f672d2e39574" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_NoncashInterestExpenseLiabilityRelatedToSaleOfFutureRoyalties_019c53e8-8c90-789b-b729-3b674553930b" xlink:href="arwr-20260331.xsd#arwr_NoncashInterestExpenseLiabilityRelatedToSaleOfFutureRoyalties"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_arwr_NoncashInterestExpenseLiabilityRelatedToSaleOfFutureRoyalties_019c53e8-8c90-789b-b729-3b674553930b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaidInKindInterest_019c53e8-8c90-7713-a8f4-50d80a091729" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaidInKindInterest"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_PaidInKindInterest_019c53e8-8c90-7713-a8f4-50d80a091729" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019c53e8-8c90-7443-bea0-71a64341886e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019c53e8-8c90-7443-bea0-71a64341886e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets1_019c53e8-8c90-7805-ba1e-b1788db8b46c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnDispositionOfAssets1"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_GainLossOnDispositionOfAssets1_019c53e8-8c90-7805-ba1e-b1788db8b46c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_NoncashTransferOfPropertyAndEquipmentToAffiliate_019c53e8-8c90-7838-b3f1-491814270cd2" xlink:href="arwr-20260331.xsd#arwr_NoncashTransferOfPropertyAndEquipmentToAffiliate"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_arwr_NoncashTransferOfPropertyAndEquipmentToAffiliate_019c53e8-8c90-7838-b3f1-491814270cd2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019c53e8-8c90-7237-a8c8-664e43eac618" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:calculationArc order="12" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019c53e8-8c90-7237-a8c8-664e43eac618" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019c53e8-8c90-7eaf-8839-ae468d94a6f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:calculationArc order="13" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019c53e8-8c90-7eaf-8839-ae468d94a6f0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable_019c53e8-8c90-7157-8b25-be8df1314816" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsPayable"/>
    <link:calculationArc order="14" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayable_019c53e8-8c90-7157-8b25-be8df1314816" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities_019d4350-ab70-726e-b446-149940982e19" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities"/>
    <link:calculationArc order="15" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities_019d4350-ab70-726e-b446-149940982e19" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_019db50b-81a6-7e1b-bb82-efd0ee60c804" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability"/>
    <link:calculationArc order="16" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_019db50b-81a6-7e1b-bb82-efd0ee60c804" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_019db50b-81a6-747f-bade-d2cbda1bb9b1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability"/>
    <link:calculationArc order="17" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_019db50b-81a6-747f-bade-d2cbda1bb9b1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_019db50b-81a6-71cf-932f-0b7710d0f03c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet"/>
    <link:calculationArc order="18" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7f95-b681-892f7d27b53e" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_019db50b-81a6-71cf-932f-0b7710d0f03c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019c53e8-8c90-720b-acc2-ae4aa393d9e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019c53e8-8c90-798b-96dd-9d6f59cc0eaa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019c53e8-8c90-720b-acc2-ae4aa393d9e0" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019c53e8-8c90-798b-96dd-9d6f59cc0eaa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_019c53e8-8c90-7acc-a07c-f07bc8510a06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019c53e8-8c90-720b-acc2-ae4aa393d9e0" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_019c53e8-8c90-7acc-a07c-f07bc8510a06" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_019c53e8-8c90-7ac0-8fd4-2eaf659b4927" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019c53e8-8c90-720b-acc2-ae4aa393d9e0" xlink:to="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_019c53e8-8c90-7ac0-8fd4-2eaf659b4927" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_019df1e6-d08e-7f0e-903b-7c48e814dc56" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019c53e8-8c90-720b-acc2-ae4aa393d9e0" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_019df1e6-d08e-7f0e-903b-7c48e814dc56" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019c53e8-8c90-78ff-b14a-c16dafd4037f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_019c53e8-8c90-763b-9138-4322470c2f43" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromStockOptionsExercised"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019c53e8-8c90-78ff-b14a-c16dafd4037f" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_019c53e8-8c90-763b-9138-4322470c2f43" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfWarrants_019c53e8-8c90-76cc-8617-145ed1857b30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfWarrants"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019c53e8-8c90-78ff-b14a-c16dafd4037f" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfWarrants_019c53e8-8c90-76cc-8617-145ed1857b30" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromConvertibleDebt_019c53e8-8c90-7eab-a207-af543609f5e4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromConvertibleDebt"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019c53e8-8c90-78ff-b14a-c16dafd4037f" xlink:to="loc_us-gaap_ProceedsFromConvertibleDebt_019c53e8-8c90-7eab-a207-af543609f5e4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019c53e8-8c90-759e-97c1-381910c2cac7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019c53e8-8c90-78ff-b14a-c16dafd4037f" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019c53e8-8c90-759e-97c1-381910c2cac7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForDerivativeInstrumentFinancingActivities_019c53e8-8c90-72c1-b463-837cb5880831" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForDerivativeInstrumentFinancingActivities"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019c53e8-8c90-78ff-b14a-c16dafd4037f" xlink:to="loc_us-gaap_PaymentsForDerivativeInstrumentFinancingActivities_019c53e8-8c90-72c1-b463-837cb5880831" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_019d435e-ad3e-783d-bf36-8dfe36a51371" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019c53e8-8c90-78ff-b14a-c16dafd4037f" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_019d435e-ad3e-783d-bf36-8dfe36a51371" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermLinesOfCredit_019d435e-ad3e-7ec4-8f1f-58e7eeb86337" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfLongTermLinesOfCredit"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019c53e8-8c90-78ff-b14a-c16dafd4037f" xlink:to="loc_us-gaap_RepaymentsOfLongTermLinesOfCredit_019d435e-ad3e-7ec4-8f1f-58e7eeb86337" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsMinorityInterest_019db50d-e6f1-7228-ac0d-d2c7b49d0011" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividendsMinorityInterest"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019c53e8-8c90-78ff-b14a-c16dafd4037f" xlink:to="loc_us-gaap_PaymentsOfDividendsMinorityInterest_019db50d-e6f1-7228-ac0d-d2c7b49d0011" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfStockIssuanceCosts_019df769-0ebd-7c0f-9f5e-6466fbe36ff5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfStockIssuanceCosts"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019c53e8-8c90-78ff-b14a-c16dafd4037f" xlink:to="loc_us-gaap_PaymentsOfStockIssuanceCosts_019df769-0ebd-7c0f-9f5e-6466fbe36ff5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_019c53e8-8c90-7be7-9df8-ccd4d8ce4e36" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7b7b-be87-ec09fad4fafa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_019c53e8-8c90-7be7-9df8-ccd4d8ce4e36" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019c53e8-8c90-7b7b-be87-ec09fad4fafa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019c53e8-8c90-75dd-9631-75116f504df0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_019c53e8-8c90-7be7-9df8-ccd4d8ce4e36" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019c53e8-8c90-75dd-9631-75116f504df0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019c53e8-8c90-7d27-88da-8cc187345e06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_019c53e8-8c90-7be7-9df8-ccd4d8ce4e36" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019c53e8-8c90-7d27-88da-8cc187345e06" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/CollaborationandLicenseAgreementsScheduleofDeferredRevenueDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#CollaborationandLicenseAgreementsScheduleofDeferredRevenueDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/CollaborationandLicenseAgreementsScheduleofDeferredRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ContractWithCustomerLiabilityNet_019c53e8-8c90-7972-a71f-afda799b646e" xlink:href="arwr-20260331.xsd#arwr_ContractWithCustomerLiabilityNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetNetCurrent_019c53e8-8c90-7356-ae32-3c40be93096d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerAssetNetCurrent"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_ContractWithCustomerLiabilityNet_019c53e8-8c90-7972-a71f-afda799b646e" xlink:to="loc_us-gaap_ContractWithCustomerAssetNetCurrent_019c53e8-8c90-7356-ae32-3c40be93096d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019c53e8-8c90-7fcd-9ab5-7ecb9b6e41b9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_ContractWithCustomerLiabilityNet_019c53e8-8c90-7972-a71f-afda799b646e" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019c53e8-8c90-7fcd-9ab5-7ecb9b6e41b9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_019c53e8-8c90-7d5e-b9ff-325edf087320" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityNoncurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_ContractWithCustomerLiabilityNet_019c53e8-8c90-7972-a71f-afda799b646e" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_019c53e8-8c90-7d5e-b9ff-325edf087320" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/BalanceSheetAccountsScheduleofPropertyPlantandEquipmentDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#BalanceSheetAccountsScheduleofPropertyPlantandEquipmentDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/BalanceSheetAccountsScheduleofPropertyPlantandEquipmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019c53e8-8d31-7db5-b238-2ddf012403e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_019c53e8-8d31-7d3e-9a84-dfafd7c0a513" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNet_019c53e8-8d31-7db5-b238-2ddf012403e8" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_019c53e8-8d31-7d3e-9a84-dfafd7c0a513" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019c53e8-8d31-75cc-8960-6bba5ea996a7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNet_019c53e8-8d31-7db5-b238-2ddf012403e8" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019c53e8-8d31-75cc-8960-6bba5ea996a7" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/BalanceSheetAccountsScheduleofAccruedExpensesDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#BalanceSheetAccountsScheduleofAccruedExpensesDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/BalanceSheetAccountsScheduleofAccruedExpensesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_019c53e8-8d31-7c36-840a-d97d62526795" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_AccruedResearchAndDevelopmentExpenseCurrent_019c53e8-8d31-7f00-b19c-c10ab7bf697a" xlink:href="arwr-20260331.xsd#arwr_AccruedResearchAndDevelopmentExpenseCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_019c53e8-8d31-7c36-840a-d97d62526795" xlink:to="loc_arwr_AccruedResearchAndDevelopmentExpenseCurrent_019c53e8-8d31-7f00-b19c-c10ab7bf697a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_AccruedResearchAndDevelopmentCoDevelopmentExpenseCurrent_019c53e8-8d31-7f8c-8e4d-3d61926c7a68" xlink:href="arwr-20260331.xsd#arwr_AccruedResearchAndDevelopmentCoDevelopmentExpenseCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_019c53e8-8d31-7c36-840a-d97d62526795" xlink:to="loc_arwr_AccruedResearchAndDevelopmentCoDevelopmentExpenseCurrent_019c53e8-8d31-7f8c-8e4d-3d61926c7a68" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_AccruedCapitalExpenditureCurrent_019c53e8-8d31-78d4-bf1d-fe673c57dbc6" xlink:href="arwr-20260331.xsd#arwr_AccruedCapitalExpenditureCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_019c53e8-8d31-7c36-840a-d97d62526795" xlink:to="loc_arwr_AccruedCapitalExpenditureCurrent_019c53e8-8d31-78d4-bf1d-fe673c57dbc6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedIncomeTaxesCurrent_019c53e8-8d31-768b-8837-f8143d23d4d3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedIncomeTaxesCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_019c53e8-8d31-7c36-840a-d97d62526795" xlink:to="loc_us-gaap_AccruedIncomeTaxesCurrent_019c53e8-8d31-768b-8837-f8143d23d4d3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableCurrent_019c53e8-8d31-756c-a59d-64440672e840" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsPayableCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_019c53e8-8d31-7c36-840a-d97d62526795" xlink:to="loc_us-gaap_DividendsPayableCurrent_019c53e8-8d31-756c-a59d-64440672e840" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAccruedLiabilitiesCurrent_019c53e8-8d31-7ab1-a33f-d4335b8c2988" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAccruedLiabilitiesCurrent"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_019c53e8-8d31-7c36-840a-d97d62526795" xlink:to="loc_us-gaap_OtherAccruedLiabilitiesCurrent_019c53e8-8d31-7ab1-a33f-d4335b8c2988" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/InvestmentsScheduleofInvestmentsDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#InvestmentsScheduleofInvestmentsDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/InvestmentsScheduleofInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostCurrent_019c53e8-8d31-7ca3-988d-190667e18251" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedLossCurrent_019c53e8-8d31-78d1-89f9-0fd4f030a08e" xlink:href="arwr-20260331.xsd#arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedLossCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostCurrent_019c53e8-8d31-7ca3-988d-190667e18251" xlink:to="loc_arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedLossCurrent_019c53e8-8d31-78d1-89f9-0fd4f030a08e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_019c53e8-8d31-7e81-b65c-1b60adaa7363" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostCurrent_019c53e8-8d31-7ca3-988d-190667e18251" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_019c53e8-8d31-7e81-b65c-1b60adaa7363" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainCurrent_019c53e8-8d31-7f5c-9cba-998bb82194d1" xlink:href="arwr-20260331.xsd#arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainCurrent"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostCurrent_019c53e8-8d31-7ca3-988d-190667e18251" xlink:to="loc_arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainCurrent_019c53e8-8d31-7f5c-9cba-998bb82194d1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_OtherShortTermInvestmentsAmortizedCost_019c53e8-8d31-7642-a261-371c61f6f7ff" xlink:href="arwr-20260331.xsd#arwr_OtherShortTermInvestmentsAmortizedCost"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ShortTermInvestmentsFairValueDisclosure_019c53e8-8d31-7faa-bf99-c4d261e21bf4" xlink:href="arwr-20260331.xsd#arwr_ShortTermInvestmentsFairValueDisclosure"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_OtherShortTermInvestmentsAmortizedCost_019c53e8-8d31-7642-a261-371c61f6f7ff" xlink:to="loc_arwr_ShortTermInvestmentsFairValueDisclosure_019c53e8-8d31-7faa-bf99-c4d261e21bf4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ShortTermInvestmentsAmortizedCost_019c53e8-8d31-7d31-af89-757ca200c385" xlink:href="arwr-20260331.xsd#arwr_ShortTermInvestmentsAmortizedCost"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainCurrent_019c53e8-8d31-760a-a46d-ddf83c74b435" xlink:href="arwr-20260331.xsd#arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainCurrent"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_ShortTermInvestmentsAmortizedCost_019c53e8-8d31-7d31-af89-757ca200c385" xlink:to="loc_arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainCurrent_019c53e8-8d31-760a-a46d-ddf83c74b435" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedLossCurrent_019c53e8-8d31-7ac6-afaa-63478a00d7cc" xlink:href="arwr-20260331.xsd#arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedLossCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_ShortTermInvestmentsAmortizedCost_019c53e8-8d31-7d31-af89-757ca200c385" xlink:to="loc_arwr_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedLossCurrent_019c53e8-8d31-7ac6-afaa-63478a00d7cc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestments_019c53e8-8d31-728d-9582-95ab30659879" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermInvestments"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_ShortTermInvestmentsAmortizedCost_019c53e8-8d31-7d31-af89-757ca200c385" xlink:to="loc_us-gaap_ShortTermInvestments_019c53e8-8d31-728d-9582-95ab30659879" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestments_019c53e8-8d31-7722-847c-b991e20b2b32" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermInvestments"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_019c53e8-8d31-784a-8bd3-1421bbbc2866" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ShortTermInvestments_019c53e8-8d31-7722-847c-b991e20b2b32" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_019c53e8-8d31-784a-8bd3-1421bbbc2866" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ShortTermInvestmentsFairValueDisclosure_019c53e8-8d31-7393-8891-f2e35784f5db" xlink:href="arwr-20260331.xsd#arwr_ShortTermInvestmentsFairValueDisclosure"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ShortTermInvestments_019c53e8-8d31-7722-847c-b991e20b2b32" xlink:to="loc_arwr_ShortTermInvestmentsFairValueDisclosure_019c53e8-8d31-7393-8891-f2e35784f5db" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/InvestmentsScheduleofContractMaturityofAvailableforSaleSecuritiesDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#InvestmentsScheduleofContractMaturityofAvailableforSaleSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/InvestmentsScheduleofContractMaturityofAvailableforSaleSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestments_019c53e8-8d31-7721-a782-a5f43fffa08e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermInvestments"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ShortTermInvestmentsFairValueMaturityAllocatedAndSingleMaturityDateRemainderOfFiscalYear_019c53e8-8d31-7b66-8423-ab451c59d7b2" xlink:href="arwr-20260331.xsd#arwr_ShortTermInvestmentsFairValueMaturityAllocatedAndSingleMaturityDateRemainderOfFiscalYear"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ShortTermInvestments_019c53e8-8d31-7721-a782-a5f43fffa08e" xlink:to="loc_arwr_ShortTermInvestmentsFairValueMaturityAllocatedAndSingleMaturityDateRemainderOfFiscalYear_019c53e8-8d31-7b66-8423-ab451c59d7b2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ShortTermInvestmentsFairValueMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughTwo_019c53e8-8d31-7a7d-8631-9975be450381" xlink:href="arwr-20260331.xsd#arwr_ShortTermInvestmentsFairValueMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughTwo"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ShortTermInvestments_019c53e8-8d31-7721-a782-a5f43fffa08e" xlink:to="loc_arwr_ShortTermInvestmentsFairValueMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughTwo_019c53e8-8d31-7a7d-8631-9975be450381" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ShortTermInvestmentsFairValueMaturityAllocatedAndSingleMaturityDateAfterYearTwoThroughThree_019d9c13-9d7c-7805-96fc-28a7ee57ffcd" xlink:href="arwr-20260331.xsd#arwr_ShortTermInvestmentsFairValueMaturityAllocatedAndSingleMaturityDateAfterYearTwoThroughThree"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ShortTermInvestments_019c53e8-8d31-7721-a782-a5f43fffa08e" xlink:to="loc_arwr_ShortTermInvestmentsFairValueMaturityAllocatedAndSingleMaturityDateAfterYearTwoThroughThree_019d9c13-9d7c-7805-96fc-28a7ee57ffcd" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/IntangibleAssetsScheduleofIntangibleAssetsDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#IntangibleAssetsScheduleofIntangibleAssetsDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/IntangibleAssetsScheduleofIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8d31-7a62-b45c-a26d6d0d3ef1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019c53e8-8d31-7605-90ab-8e3dcfa5d235" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8d31-7a62-b45c-a26d6d0d3ef1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019c53e8-8d31-7605-90ab-8e3dcfa5d235" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019c53e8-8d31-7e0a-a2b9-f9e52829b5c8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8d31-7a62-b45c-a26d6d0d3ef1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019c53e8-8d31-7e0a-a2b9-f9e52829b5c8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_FiniteLivedIntangibleAssetsImpairment_019c53e8-8d31-7ecd-a381-d15c43b8d120" xlink:href="arwr-20260331.xsd#arwr_FiniteLivedIntangibleAssetsImpairment"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8d31-7a62-b45c-a26d6d0d3ef1" xlink:to="loc_arwr_FiniteLivedIntangibleAssetsImpairment_019c53e8-8d31-7ecd-a381-d15c43b8d120" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/IntangibleAssetsScheduleofExpectedFutureAmortizationDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#IntangibleAssetsScheduleofExpectedFutureAmortizationDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/IntangibleAssetsScheduleofExpectedFutureAmortizationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8d31-7b6b-aeec-906189796a77" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_019c53e8-8d31-7eda-b0c5-1d18a7c884a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8d31-7b6b-aeec-906189796a77" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_019c53e8-8d31-7eda-b0c5-1d18a7c884a9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_019c53e8-8d31-73b5-880c-97323c3e518d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8d31-7b6b-aeec-906189796a77" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_019c53e8-8d31-73b5-880c-97323c3e518d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_019c53e8-8d31-7092-8ed2-922f3da9b4eb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8d31-7b6b-aeec-906189796a77" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_019c53e8-8d31-7092-8ed2-922f3da9b4eb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_019c53e8-8d31-72eb-8454-aaabee26b79c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8d31-7b6b-aeec-906189796a77" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_019c53e8-8d31-72eb-8454-aaabee26b79c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_019c53e8-8d31-7746-8d69-66a04397a71e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8d31-7b6b-aeec-906189796a77" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_019c53e8-8d31-7746-8d69-66a04397a71e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_FiniteLivedIntangibleAssetExpectedAmortizationAfterYearFour_019c53e8-8d31-71dc-b6bf-c17d3ba7485a" xlink:href="arwr-20260331.xsd#arwr_FiniteLivedIntangibleAssetExpectedAmortizationAfterYearFour"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c53e8-8d31-7b6b-aeec-906189796a77" xlink:to="loc_arwr_FiniteLivedIntangibleAssetExpectedAmortizationAfterYearFour_019c53e8-8d31-71dc-b6bf-c17d3ba7485a" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/LeasesScheduleofLeaseAssetsandLiabilitiesandLeaseCostDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#LeasesScheduleofLeaseAssetsandLiabilitiesandLeaseCostDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/LeasesScheduleofLeaseAssetsandLiabilitiesandLeaseCostDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCost_019c53e8-8d31-770f-8636-f44a6a53d7c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCost"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableLeaseCost_019c53e8-8d31-7a68-aaca-66ad5c784ab9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableLeaseCost"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019c53e8-8d31-770f-8636-f44a6a53d7c1" xlink:to="loc_us-gaap_VariableLeaseCost_019c53e8-8d31-7a68-aaca-66ad5c784ab9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseCost_019c53e8-8d31-7071-8592-ead066711837" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019c53e8-8d31-770f-8636-f44a6a53d7c1" xlink:to="loc_us-gaap_OperatingLeaseCost_019c53e8-8d31-7071-8592-ead066711837" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/LeasesScheduleofMaturitiesofOperatingLeaseLiabilitiesonanUndiscountedBasisDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#LeasesScheduleofMaturitiesofOperatingLeaseLiabilitiesonanUndiscountedBasisDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/LeasesScheduleofMaturitiesofOperatingLeaseLiabilitiesonanUndiscountedBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019c53e8-8d31-7353-9811-ce04df06f3c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_019c53e8-8d31-7984-a682-d09b6f2eff4b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019c53e8-8d31-7353-9811-ce04df06f3c7" xlink:to="loc_us-gaap_OperatingLeaseLiability_019c53e8-8d31-7984-a682-d09b6f2eff4b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_019c53e8-8d31-7106-becd-2c25ba1be777" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019c53e8-8d31-7353-9811-ce04df06f3c7" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_019c53e8-8d31-7106-becd-2c25ba1be777" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/LeasesScheduleofMaturitiesofOperatingLeaseLiabilitiesonanUndiscountedBasisDetails_1" xlink:type="simple" xlink:href="arwr-20260331.xsd#LeasesScheduleofMaturitiesofOperatingLeaseLiabilitiesonanUndiscountedBasisDetails_1"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/LeasesScheduleofMaturitiesofOperatingLeaseLiabilitiesonanUndiscountedBasisDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019c53e8-8d31-7183-b232-1a1be6bbd609" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_019c53e8-8d31-7572-b25e-7e8f434d5d13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019c53e8-8d31-7183-b232-1a1be6bbd609" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_019c53e8-8d31-7572-b25e-7e8f434d5d13" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_019c53e8-8d31-7fad-b123-120f370589d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019c53e8-8d31-7183-b232-1a1be6bbd609" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_019c53e8-8d31-7fad-b123-120f370589d4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_019c53e8-8d32-759b-8c7a-a332114ea976" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019c53e8-8d31-7183-b232-1a1be6bbd609" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_019c53e8-8d32-759b-8c7a-a332114ea976" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_019c53e8-8d32-7d38-a661-68c401c5e8c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019c53e8-8d31-7183-b232-1a1be6bbd609" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_019c53e8-8d32-7d38-a661-68c401c5e8c6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_LesseeOperatingLeaseLiabilityToBePaidYearFiveAndAfterYearFive_019c53e8-8d32-7f87-b67f-4c37cf4ca696" xlink:href="arwr-20260331.xsd#arwr_LesseeOperatingLeaseLiabilityToBePaidYearFiveAndAfterYearFive"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019c53e8-8d31-7183-b232-1a1be6bbd609" xlink:to="loc_arwr_LesseeOperatingLeaseLiabilityToBePaidYearFiveAndAfterYearFive_019c53e8-8d32-7f87-b67f-4c37cf4ca696" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_019c53e8-8d32-7c5c-9113-370757c5cff4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019c53e8-8d31-7183-b232-1a1be6bbd609" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_019c53e8-8d32-7c5c-9113-370757c5cff4" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/StockBasedCompensationScheduleofAwardsOutstandingDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#StockBasedCompensationScheduleofAwardsOutstandingDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/StockBasedCompensationScheduleofAwardsOutstandingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndEquityInstrumentsOtherThanOptionsOutstanding_019c53e8-8d32-72ef-84b4-7de2cafed8c2" xlink:href="arwr-20260331.xsd#arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndEquityInstrumentsOtherThanOptionsOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_019c53e8-8d32-771c-a67f-2cb277402eba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndEquityInstrumentsOtherThanOptionsOutstanding_019c53e8-8d32-72ef-84b4-7de2cafed8c2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_019c53e8-8d32-771c-a67f-2cb277402eba" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019c53e8-8d32-7ef6-9ca6-09b027b41b30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndEquityInstrumentsOtherThanOptionsOutstanding_019c53e8-8d32-72ef-84b4-7de2cafed8c2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019c53e8-8d32-7ef6-9ca6-09b027b41b30" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/FairValueMeasurementsScheduleofFairValueMeasurementsforAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#FairValueMeasurementsScheduleofFairValueMeasurementsforAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/FairValueMeasurementsScheduleofFairValueMeasurementsforAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_019c53e8-8d32-732b-866d-8b2ee63f1b35" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019c53e8-8d32-7221-b58b-f4691d36f228" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019c53e8-8d32-732b-866d-8b2ee63f1b35" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019c53e8-8d32-7221-b58b-f4691d36f228" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ShortTermInvestmentsFairValueDisclosure_019c53e8-8d32-7c87-bc01-69d9fe3ef2bd" xlink:href="arwr-20260331.xsd#arwr_ShortTermInvestmentsFairValueDisclosure"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019c53e8-8d32-732b-866d-8b2ee63f1b35" xlink:to="loc_arwr_ShortTermInvestmentsFairValueDisclosure_019c53e8-8d32-7c87-bc01-69d9fe3ef2bd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019c53e8-8d32-7ad6-981e-e88c1839b991" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019c53e8-8d32-732b-866d-8b2ee63f1b35" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019c53e8-8d32-7ad6-981e-e88c1839b991" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/FinancingAgreementScheduleofTotalInterestExpenseRecognizedDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#FinancingAgreementScheduleofTotalInterestExpenseRecognizedDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/FinancingAgreementScheduleofTotalInterestExpenseRecognizedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_019c53e8-8d32-7ccb-ade0-009bff127d73" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseDebt"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebtExcludingAmortization_019c53e8-8d32-70db-ba26-75e6822cdb7e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseDebtExcludingAmortization"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseDebt_019c53e8-8d32-7ccb-ade0-009bff127d73" xlink:to="loc_us-gaap_InterestExpenseDebtExcludingAmortization_019c53e8-8d32-70db-ba26-75e6822cdb7e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_019c53e8-8d32-753a-b272-4031d6a8cb21" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseDebt_019c53e8-8d32-7ccb-ade0-009bff127d73" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_019c53e8-8d32-753a-b272-4031d6a8cb21" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfDebtDiscountPremium_019c53e8-8d32-756c-bc3e-decd998f809c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfDebtDiscountPremium"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseDebt_019c53e8-8d32-7ccb-ade0-009bff127d73" xlink:to="loc_us-gaap_AmortizationOfDebtDiscountPremium_019c53e8-8d32-756c-bc3e-decd998f809c" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/FinancingAgreementScheduleofPrincipalRepaymentRelatedtoCreditFacilityDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#FinancingAgreementScheduleofPrincipalRepaymentRelatedtoCreditFacilityDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/FinancingAgreementScheduleofPrincipalRepaymentRelatedtoCreditFacilityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019c53e8-8d32-731f-92da-1aa57a7a9e55" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_019c53e8-8d32-7897-b007-0ab081a2ee84" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount_019c53e8-8d32-731f-92da-1aa57a7a9e55" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_019c53e8-8d32-7897-b007-0ab081a2ee84" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear_019c53e8-8d32-76ad-9e7b-209690ac6969" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount_019c53e8-8d32-731f-92da-1aa57a7a9e55" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear_019c53e8-8d32-76ad-9e7b-209690ac6969" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_019c53e8-8d32-755b-a7fe-f7acc323eb36" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount_019c53e8-8d32-731f-92da-1aa57a7a9e55" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_019c53e8-8d32-755b-a7fe-f7acc323eb36" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_019c53e8-8d32-7981-af36-b1429c621ecd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount_019c53e8-8d32-731f-92da-1aa57a7a9e55" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_019c53e8-8d32-7981-af36-b1429c621ecd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_LongTermDebtMaturityAfterYearFour_019c53e8-8d32-708a-b27d-d3609f30f3d0" xlink:href="arwr-20260331.xsd#arwr_LongTermDebtMaturityAfterYearFour"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount_019c53e8-8d32-731f-92da-1aa57a7a9e55" xlink:to="loc_arwr_LongTermDebtMaturityAfterYearFour_019c53e8-8d32-708a-b27d-d3609f30f3d0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_019c53e8-8d32-78db-ac27-515304aa93e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount_019c53e8-8d32-731f-92da-1aa57a7a9e55" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_019c53e8-8d32-78db-ac27-515304aa93e6" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/ConvertibleNotesScheduleofConvertibleDebtDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#ConvertibleNotesScheduleofConvertibleDebtDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/ConvertibleNotesScheduleofConvertibleDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019dda61-3465-7175-b140-eac2583f2abf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019dda61-3465-7fd4-8fc6-791821779ed7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_019dda61-3465-7175-b140-eac2583f2abf" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019dda61-3465-7fd4-8fc6-791821779ed7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_019dda61-3465-729b-a2d5-16d8f4724cc1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_019dda61-3465-7175-b140-eac2583f2abf" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_019dda61-3465-729b-a2d5-16d8f4724cc1" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/NetLossIncomePerShareScheduleofComputationofBasicandDilutedNetLossIncomePerShareDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#NetLossIncomePerShareScheduleofComputationofBasicandDilutedNetLossIncomePerShareDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/NetLossIncomePerShareScheduleofComputationofBasicandDilutedNetLossIncomePerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019c53e8-8d32-7711-b0a3-a6252a0647a5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_019c53e8-8d32-7c27-b7fb-e9f0091b313d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019c53e8-8d32-7711-b0a3-a6252a0647a5" xlink:to="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_019c53e8-8d32-7c27-b7fb-e9f0091b313d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019c53e8-8d32-75e8-b8ca-0a39b6080b32" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019c53e8-8d32-7711-b0a3-a6252a0647a5" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019c53e8-8d32-75e8-b8ca-0a39b6080b32" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.arrowheadresearch.com/role/SegmentInformationScheduleofResearchandDevelopmentandSellingGeneralandAdministrativeExpensesDetails" xlink:type="simple" xlink:href="arwr-20260331.xsd#SegmentInformationScheduleofResearchandDevelopmentandSellingGeneralandAdministrativeExpensesDetails"/>
  <link:calculationLink xlink:role="http://www.arrowheadresearch.com/role/SegmentInformationScheduleofResearchandDevelopmentandSellingGeneralandAdministrativeExpensesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_019c53e8-8d32-7c00-9112-6a2cda7a81f5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ResearchAndDevelopmentExpenseExcludingNoncashExpense_019c53e8-8d32-794e-b29c-be4104be8ba7" xlink:href="arwr-20260331.xsd#arwr_ResearchAndDevelopmentExpenseExcludingNoncashExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ResearchAndDevelopmentExpense_019c53e8-8d32-7c00-9112-6a2cda7a81f5" xlink:to="loc_arwr_ResearchAndDevelopmentExpenseExcludingNoncashExpense_019c53e8-8d32-794e-b29c-be4104be8ba7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019c53e8-8d32-754d-aa9d-4487df2399c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ResearchAndDevelopmentExpense_019c53e8-8d32-7c00-9112-6a2cda7a81f5" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019c53e8-8d32-754d-aa9d-4487df2399c0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019c53e8-8d32-7038-9e0c-e8613d62409a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ResearchAndDevelopmentExpense_019c53e8-8d32-7c00-9112-6a2cda7a81f5" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019c53e8-8d32-7038-9e0c-e8613d62409a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_SellingGeneralAndAdministrativeExpenseExcludingNoncashExpense_019c53e8-8d32-7e5c-b85d-853b52d0fc9b" xlink:href="arwr-20260331.xsd#arwr_SellingGeneralAndAdministrativeExpenseExcludingNoncashExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalariesWagesAndOfficersCompensation_019c53e8-8d32-7818-ac1a-211ed3741fdc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SalariesWagesAndOfficersCompensation"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_SellingGeneralAndAdministrativeExpenseExcludingNoncashExpense_019c53e8-8d32-7e5c-b85d-853b52d0fc9b" xlink:to="loc_us-gaap_SalariesWagesAndOfficersCompensation_019c53e8-8d32-7818-ac1a-211ed3741fdc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_019c53e8-8d32-7f5e-bf02-5121c618d108" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfessionalFees"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_SellingGeneralAndAdministrativeExpenseExcludingNoncashExpense_019c53e8-8d32-7e5c-b85d-853b52d0fc9b" xlink:to="loc_us-gaap_ProfessionalFees_019c53e8-8d32-7f5e-bf02-5121c618d108" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_SellingGeneralAndAdministrativeExpenseFacilitiesRelatedExpense_019c53e8-8d32-74fc-a9d1-d3fe6866947e" xlink:href="arwr-20260331.xsd#arwr_SellingGeneralAndAdministrativeExpenseFacilitiesRelatedExpense"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_SellingGeneralAndAdministrativeExpenseExcludingNoncashExpense_019c53e8-8d32-7e5c-b85d-853b52d0fc9b" xlink:to="loc_arwr_SellingGeneralAndAdministrativeExpenseFacilitiesRelatedExpense_019c53e8-8d32-74fc-a9d1-d3fe6866947e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ResearchAndDevelopmentExpenseExcludingNoncashExpense_019c53e8-8d32-741b-91ba-1a51c288419d" xlink:href="arwr-20260331.xsd#arwr_ResearchAndDevelopmentExpenseExcludingNoncashExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ResearchAndDevelopmentExpenseCandidateCosts_019c53e8-8d32-7aea-9020-b3e6aadd3f44" xlink:href="arwr-20260331.xsd#arwr_ResearchAndDevelopmentExpenseCandidateCosts"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_ResearchAndDevelopmentExpenseExcludingNoncashExpense_019c53e8-8d32-741b-91ba-1a51c288419d" xlink:to="loc_arwr_ResearchAndDevelopmentExpenseCandidateCosts_019c53e8-8d32-7aea-9020-b3e6aadd3f44" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ResearchAndDevelopmentExpenseDiscoveryCosts_019c53e8-8d32-7437-8be4-7814a8b64ca3" xlink:href="arwr-20260331.xsd#arwr_ResearchAndDevelopmentExpenseDiscoveryCosts"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_ResearchAndDevelopmentExpenseExcludingNoncashExpense_019c53e8-8d32-741b-91ba-1a51c288419d" xlink:to="loc_arwr_ResearchAndDevelopmentExpenseDiscoveryCosts_019c53e8-8d32-7437-8be4-7814a8b64ca3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ResearchAndDevelopmentExpenseSalariesExpense_019c53e8-8d32-79e0-b911-085da3484116" xlink:href="arwr-20260331.xsd#arwr_ResearchAndDevelopmentExpenseSalariesExpense"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_ResearchAndDevelopmentExpenseExcludingNoncashExpense_019c53e8-8d32-741b-91ba-1a51c288419d" xlink:to="loc_arwr_ResearchAndDevelopmentExpenseSalariesExpense_019c53e8-8d32-79e0-b911-085da3484116" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_ResearchAndDevelopmentExpenseFacilitiesRelatedExpense_019c53e8-8d32-796b-a2ef-07b3b087bea1" xlink:href="arwr-20260331.xsd#arwr_ResearchAndDevelopmentExpenseFacilitiesRelatedExpense"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_arwr_ResearchAndDevelopmentExpenseExcludingNoncashExpense_019c53e8-8d32-741b-91ba-1a51c288419d" xlink:to="loc_arwr_ResearchAndDevelopmentExpenseFacilitiesRelatedExpense_019c53e8-8d32-796b-a2ef-07b3b087bea1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019de5b9-2a1d-7ad3-92dc-52a47cd663b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_arwr_SellingGeneralAndAdministrativeExpenseExcludingNoncashExpense_019de5b9-2a1d-7538-be20-d6a3639437f3" xlink:href="arwr-20260331.xsd#arwr_SellingGeneralAndAdministrativeExpenseExcludingNoncashExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019de5b9-2a1d-7ad3-92dc-52a47cd663b4" xlink:to="loc_arwr_SellingGeneralAndAdministrativeExpenseExcludingNoncashExpense_019de5b9-2a1d-7538-be20-d6a3639437f3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019de5b9-2a1d-7e0d-abf5-77b99d529e43" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019de5b9-2a1d-7ad3-92dc-52a47cd663b4" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019de5b9-2a1d-7e0d-abf5-77b99d529e43" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019de5b9-2a1d-7a46-ba18-67fb1dce972d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019de5b9-2a1d-7ad3-92dc-52a47cd663b4" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019de5b9-2a1d-7a46-ba18-67fb1dce972d" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
