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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e6579-31ea-7ed5-9862-f7db9b4978a9,g:ff1b9047-5fea-44c6-b597-ec7ded892696-->
<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:roleRef roleURI="http://owlrockcapitalcorporation.com/role/ConsolidatedStatementsofAssetsandLiabilities" xlink:type="simple" xlink:href="ortf-20260630.xsd#ConsolidatedStatementsofAssetsandLiabilities"/>
  <link:calculationLink xlink:role="http://owlrockcapitalcorporation.com/role/ConsolidatedStatementsofAssetsandLiabilities" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019e6579-4389-7a00-aaf6-db1d134fb20c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019e6579-4389-7419-90e3-4ece14d0afea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6579-4389-7a00-aaf6-db1d134fb20c" xlink:to="loc_us-gaap_LongTermDebt_019e6579-4389-7419-90e3-4ece14d0afea" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DistributionPayable_019e6579-4389-70a4-ba7e-2c728da6bac4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DistributionPayable"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6579-4389-7a00-aaf6-db1d134fb20c" xlink:to="loc_us-gaap_DistributionPayable_019e6579-4389-70a4-ba7e-2c728da6bac4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementFeePayable_019e6579-4389-78bc-a837-355920b6b490" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ManagementFeePayable"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6579-4389-7a00-aaf6-db1d134fb20c" xlink:to="loc_us-gaap_ManagementFeePayable_019e6579-4389-78bc-a837-355920b6b490" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncentiveFeePayable_019e6579-4389-77b2-841f-0de4830b57e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncentiveFeePayable"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6579-4389-7a00-aaf6-db1d134fb20c" xlink:to="loc_us-gaap_IncentiveFeePayable_019e6579-4389-77b2-841f-0de4830b57e8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilities_019e6579-4389-7958-b790-a314289e3a5c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilities"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6579-4389-7a00-aaf6-db1d134fb20c" xlink:to="loc_us-gaap_OtherLiabilities_019e6579-4389-7958-b790-a314289e3a5c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PayableInvestmentPurchase_019e6579-4389-708e-9b43-40a0c306781d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PayableInvestmentPurchase"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6579-4389-7a00-aaf6-db1d134fb20c" xlink:to="loc_us-gaap_PayableInvestmentPurchase_019e6579-4389-708e-9b43-40a0c306781d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesAndOtherLiabilities_019e6579-4389-7142-afc7-c999653c55af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesAndOtherLiabilities"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6579-4389-7a00-aaf6-db1d134fb20c" xlink:to="loc_us-gaap_AccruedLiabilitiesAndOtherLiabilities_019e6579-4389-7142-afc7-c999653c55af" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e6579-4389-72f0-96bd-263a02933c34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019e6579-4389-78ba-9794-15a234471ade" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019e6579-4389-72f0-96bd-263a02933c34" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019e6579-4389-78ba-9794-15a234471ade" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019e6579-4389-7489-8f40-e1c8ceb74f7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019e6579-4389-72f0-96bd-263a02933c34" xlink:to="loc_us-gaap_CommonStockValue_019e6579-4389-7489-8f40-e1c8ceb74f7a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_019e6579-4389-73ed-9f3f-5468f936530b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019e6579-4389-72f0-96bd-263a02933c34" xlink:to="loc_us-gaap_AdditionalPaidInCapital_019e6579-4389-73ed-9f3f-5468f936530b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e6579-4389-777f-8084-d0814ecf001b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019e6579-4389-7854-8b7b-fae38e07029e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e6579-4389-777f-8084-d0814ecf001b" xlink:to="loc_us-gaap_Liabilities_019e6579-4389-7854-8b7b-fae38e07029e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_019e6579-4389-75a5-8e17-207898904139" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e6579-4389-777f-8084-d0814ecf001b" xlink:to="loc_us-gaap_CommitmentsAndContingencies_019e6579-4389-75a5-8e17-207898904139" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e6579-4389-7825-8db0-1fbf11bde70f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e6579-4389-777f-8084-d0814ecf001b" xlink:to="loc_us-gaap_StockholdersEquity_019e6579-4389-7825-8db0-1fbf11bde70f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019e6579-4389-7836-82b2-d9765fdfb972" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_019e6579-4389-7063-8c48-5847122605a4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6579-4389-7836-82b2-d9765fdfb972" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_019e6579-4389-7063-8c48-5847122605a4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019e6579-4389-7e12-a7ca-eba4284bdbdb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6579-4389-7836-82b2-d9765fdfb972" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019e6579-4389-7e12-a7ca-eba4284bdbdb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashHeldInForeignCurrency_019e6579-4389-750c-87a9-b84c0ebedbe2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashHeldInForeignCurrency"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6579-4389-7836-82b2-d9765fdfb972" xlink:to="loc_us-gaap_CashHeldInForeignCurrency_019e6579-4389-750c-87a9-b84c0ebedbe2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendAndInterestReceivable_019e6579-4389-7dcc-970e-49870fad5415" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendAndInterestReceivable"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6579-4389-7836-82b2-d9765fdfb972" xlink:to="loc_us-gaap_DividendAndInterestReceivable_019e6579-4389-7dcc-970e-49870fad5415" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherReceivables_019e6579-4389-7acb-b2fb-05cbb45d2c1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherReceivables"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6579-4389-7836-82b2-d9765fdfb972" xlink:to="loc_us-gaap_OtherReceivables_019e6579-4389-7acb-b2fb-05cbb45d2c1e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssets_019e6579-4389-777f-b8dd-24fffc4efb17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrepaidExpenseAndOtherAssets"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6579-4389-7836-82b2-d9765fdfb972" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssets_019e6579-4389-777f-b8dd-24fffc4efb17" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://owlrockcapitalcorporation.com/role/ConsolidatedStatementsofOperations" xlink:type="simple" xlink:href="ortf-20260630.xsd#ConsolidatedStatementsofOperations"/>
  <link:calculationLink xlink:role="http://owlrockcapitalcorporation.com/role/ConsolidatedStatementsofOperations" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetInvestmentIncome_019e6579-4389-7d6d-af55-54287a625ba4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetInvestmentIncome"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInvestmentExpense_019e6579-4389-77bf-b983-2386bbab7d87" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeInvestmentExpense"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetInvestmentIncome_019e6579-4389-7d6d-af55-54287a625ba4" xlink:to="loc_us-gaap_InvestmentIncomeInvestmentExpense_019e6579-4389-77bf-b983-2386bbab7d87" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossInvestmentIncomeOperating_019e6579-4389-747e-939e-0caa42b28f3f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossInvestmentIncomeOperating"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetInvestmentIncome_019e6579-4389-7d6d-af55-54287a625ba4" xlink:to="loc_us-gaap_GrossInvestmentIncomeOperating_019e6579-4389-747e-939e-0caa42b28f3f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossInvestmentIncomeOperating_019e6579-4389-7df5-8e4c-4abb1a8ab9ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossInvestmentIncomeOperating"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendIncomeOperating_019e6579-4389-796a-9a33-6ff5a1c9e027" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendIncomeOperating"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossInvestmentIncomeOperating_019e6579-4389-7df5-8e4c-4abb1a8ab9ce" xlink:to="loc_us-gaap_DividendIncomeOperating_019e6579-4389-796a-9a33-6ff5a1c9e027" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeOperating_019e6579-4389-73f2-916e-0a3abd220c27" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeOperating"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossInvestmentIncomeOperating_019e6579-4389-7df5-8e4c-4abb1a8ab9ce" xlink:to="loc_us-gaap_InterestIncomeOperating_019e6579-4389-73f2-916e-0a3abd220c27" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIncome_019e6579-4389-7d91-a8a6-2782769e0939" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherIncome"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossInvestmentIncomeOperating_019e6579-4389-7df5-8e4c-4abb1a8ab9ce" xlink:to="loc_us-gaap_OtherIncome_019e6579-4389-7d91-a8a6-2782769e0939" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeOperatingPaidInKind_019e6579-4389-76a6-b3f5-008327a4c041" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeOperatingPaidInKind"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossInvestmentIncomeOperating_019e6579-4389-7df5-8e4c-4abb1a8ab9ce" xlink:to="loc_us-gaap_InterestIncomeOperatingPaidInKind_019e6579-4389-76a6-b3f5-008327a4c041" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendIncomeOperatingPaidInKind_019e6579-4389-7c2c-b76b-8d37e61cfca6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendIncomeOperatingPaidInKind"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossInvestmentIncomeOperating_019e6579-4389-7df5-8e4c-4abb1a8ab9ce" xlink:to="loc_us-gaap_DividendIncomeOperatingPaidInKind_019e6579-4389-7c2c-b76b-8d37e61cfca6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_019e6579-4389-7dfd-8e02-638eab8b3ede" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossUnrealized_019e6579-4389-7016-b674-0a86bad24544" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyTransactionGainLossUnrealized"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_UnrealizedGainLossOnInvestments_019e6579-4389-7dfd-8e02-638eab8b3ede" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossUnrealized_019e6579-4389-7016-b674-0a86bad24544" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_019e6579-4389-73fa-a3a8-6388ac9761f4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_UnrealizedGainLossOnInvestments_019e6579-4389-7dfd-8e02-638eab8b3ede" xlink:to="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_019e6579-4389-73fa-a3a8-6388ac9761f4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossInvestmentAndDerivativeOperatingTaxExpenseBenefit_019e6579-4389-7213-bf8a-a2accc28b46e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrealizedGainLossInvestmentAndDerivativeOperatingTaxExpenseBenefit"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_UnrealizedGainLossOnInvestments_019e6579-4389-7dfd-8e02-638eab8b3ede" xlink:to="loc_us-gaap_UnrealizedGainLossInvestmentAndDerivativeOperatingTaxExpenseBenefit_019e6579-4389-7213-bf8a-a2accc28b46e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeOperatingAfterExpenseAndTax_019e6579-4389-78eb-9a58-5d9750d834d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeOperatingAfterExpenseAndTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetInvestmentIncome_019e6579-4389-770c-b95c-f70cba3099f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetInvestmentIncome"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentIncomeOperatingAfterExpenseAndTax_019e6579-4389-78eb-9a58-5d9750d834d3" xlink:to="loc_us-gaap_NetInvestmentIncome_019e6579-4389-770c-b95c-f70cba3099f9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeOperatingTaxExpenseBenefit_019e6579-4389-7a7a-8fb6-f8469ef43c48" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeOperatingTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentIncomeOperatingAfterExpenseAndTax_019e6579-4389-78eb-9a58-5d9750d834d3" xlink:to="loc_us-gaap_InvestmentIncomeOperatingTaxExpenseBenefit_019e6579-4389-7a7a-8fb6-f8469ef43c48" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e6579-4389-7624-93ef-7234748c1184" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedAndUnrealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionOperatingAfterTax_019e6579-4389-7b14-8dd9-53a57fe20116" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RealizedAndUnrealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionOperatingAfterTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019e6579-4389-7624-93ef-7234748c1184" xlink:to="loc_us-gaap_RealizedAndUnrealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionOperatingAfterTax_019e6579-4389-7b14-8dd9-53a57fe20116" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeOperatingAfterExpenseAndTax_019e6579-4389-7f34-a978-ab5e5aab54f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeOperatingAfterExpenseAndTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019e6579-4389-7624-93ef-7234748c1184" xlink:to="loc_us-gaap_InvestmentIncomeOperatingAfterExpenseAndTax_019e6579-4389-7f34-a978-ab5e5aab54f2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInvestmentExpense_019e6579-4389-7070-86ca-5990d88ebcf9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeInvestmentExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_019e6579-4389-7292-94c6-06dbb7ecf2d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentIncomeInvestmentExpense_019e6579-4389-7070-86ca-5990d88ebcf9" xlink:to="loc_us-gaap_InterestExpense_019e6579-4389-7292-94c6-06dbb7ecf2d2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ManagementFeeExpense_019e6579-4389-70d2-9c4d-b43b35e37142" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ManagementFeeExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentIncomeInvestmentExpense_019e6579-4389-7070-86ca-5990d88ebcf9" xlink:to="loc_us-gaap_ManagementFeeExpense_019e6579-4389-70d2-9c4d-b43b35e37142" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_IncentiveFeeExpenseReversalNet_019e6579-4389-7f92-9b8f-d9b43549d90c" xlink:href="ortf-20260630.xsd#ortf_IncentiveFeeExpenseReversalNet"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentIncomeInvestmentExpense_019e6579-4389-7070-86ca-5990d88ebcf9" xlink:to="loc_ortf_IncentiveFeeExpenseReversalNet_019e6579-4389-7f92-9b8f-d9b43549d90c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_019e6579-4389-7594-97be-fabbe7464c93" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfessionalFees"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentIncomeInvestmentExpense_019e6579-4389-7070-86ca-5990d88ebcf9" xlink:to="loc_us-gaap_ProfessionalFees_019e6579-4389-7594-97be-fabbe7464c93" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpenseInvestmentAdvisoryFees_019e6579-4389-709a-94c5-887b9b321260" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestExpenseInvestmentAdvisoryFees"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentIncomeInvestmentExpense_019e6579-4389-7070-86ca-5990d88ebcf9" xlink:to="loc_us-gaap_NoninterestExpenseInvestmentAdvisoryFees_019e6579-4389-709a-94c5-887b9b321260" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpenseDirectorsFees_019e6579-4389-7fff-af27-e2cbad5740ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestExpenseDirectorsFees"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentIncomeInvestmentExpense_019e6579-4389-7070-86ca-5990d88ebcf9" xlink:to="loc_us-gaap_NoninterestExpenseDirectorsFees_019e6579-4389-7fff-af27-e2cbad5740ef" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherGeneralAndAdministrativeExpense_019ec9eb-ab94-7965-8f87-eebf92afd2dd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherGeneralAndAdministrativeExpense"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentIncomeInvestmentExpense_019e6579-4389-7070-86ca-5990d88ebcf9" xlink:to="loc_us-gaap_OtherGeneralAndAdministrativeExpense_019ec9eb-ab94-7965-8f87-eebf92afd2dd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedAndUnrealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionOperatingAfterTax_019e6579-4389-7e13-b6b3-df1af77cc664" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RealizedAndUnrealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionOperatingAfterTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_019e6579-4389-78ba-9c82-dd74ff659ba8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_RealizedAndUnrealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionOperatingAfterTax_019e6579-4389-7e13-b6b3-df1af77cc664" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_019e6579-4389-78ba-9c82-dd74ff659ba8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_019e6579-4389-7083-865b-61e51002a19f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RealizedInvestmentGainsLosses"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_RealizedAndUnrealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionOperatingAfterTax_019e6579-4389-7e13-b6b3-df1af77cc664" xlink:to="loc_us-gaap_RealizedInvestmentGainsLosses_019e6579-4389-7083-865b-61e51002a19f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_019e6579-4389-7bb2-9358-285a2a4e992f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RealizedInvestmentGainsLosses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndEquitySecuritiesRealizedGainLoss_019e6579-4389-791c-b4f3-2b0b0649d1ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtAndEquitySecuritiesRealizedGainLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_RealizedInvestmentGainsLosses_019e6579-4389-7bb2-9358-285a2a4e992f" xlink:to="loc_us-gaap_DebtAndEquitySecuritiesRealizedGainLoss_019e6579-4389-791c-b4f3-2b0b0649d1ca" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossRealized_019e6579-4389-7800-b12a-50b63404bf79" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyTransactionGainLossRealized"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_RealizedInvestmentGainsLosses_019e6579-4389-7bb2-9358-285a2a4e992f" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossRealized_019e6579-4389-7800-b12a-50b63404bf79" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://owlrockcapitalcorporation.com/role/ConsolidatedStatementsofChangesinNetAssets" xlink:type="simple" xlink:href="ortf-20260630.xsd#ConsolidatedStatementsofChangesinNetAssets"/>
  <link:calculationLink xlink:role="http://owlrockcapitalcorporation.com/role/ConsolidatedStatementsofChangesinNetAssets" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityPeriodIncreaseDecrease_019ecbb3-bd2e-7659-b187-158044c2b758" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityPeriodIncreaseDecrease"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019ecbb3-bd2e-7242-ba30-c6cd73fed552" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityPeriodIncreaseDecrease_019ecbb3-bd2e-7659-b187-158044c2b758" xlink:to="loc_us-gaap_NetIncomeLoss_019ecbb3-bd2e-7242-ba30-c6cd73fed552" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyDividendDistribution_019ecbb3-bd2e-7c01-a5f5-6a06b91190e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyDividendDistribution"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityPeriodIncreaseDecrease_019ecbb3-bd2e-7659-b187-158044c2b758" xlink:to="loc_us-gaap_InvestmentCompanyDividendDistribution_019ecbb3-bd2e-7c01-a5f5-6a06b91190e1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_InvestmentCompanyCapitalTransactionsIncreaseDecrease_019ecbb3-bd2e-7778-b3b9-119d87729cee" xlink:href="ortf-20260630.xsd#ortf_InvestmentCompanyCapitalTransactionsIncreaseDecrease"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityPeriodIncreaseDecrease_019ecbb3-bd2e-7659-b187-158044c2b758" xlink:to="loc_ortf_InvestmentCompanyCapitalTransactionsIncreaseDecrease_019ecbb3-bd2e-7778-b3b9-119d87729cee" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_InvestmentCompanyCapitalTransactionsIncreaseDecrease_019ecbb3-bd2e-7f27-bee5-73a22a9b6f6c" xlink:href="ortf-20260630.xsd#ortf_InvestmentCompanyCapitalTransactionsIncreaseDecrease"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_019ecbb3-bd2e-74f5-9439-f758a37563b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_InvestmentCompanyCapitalTransactionsIncreaseDecrease_019ecbb3-bd2e-7f27-bee5-73a22a9b6f6c" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_019ecbb3-bd2e-74f5-9439-f758a37563b9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_019ecbb3-bd2e-791f-bb6b-f4a7a14f382d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_InvestmentCompanyCapitalTransactionsIncreaseDecrease_019ecbb3-bd2e-7f27-bee5-73a22a9b6f6c" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_019ecbb3-bd2e-791f-bb6b-f4a7a14f382d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions_019ecbb3-bd2e-705b-8f31-5342089462cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_InvestmentCompanyCapitalTransactionsIncreaseDecrease_019ecbb3-bd2e-7f27-bee5-73a22a9b6f6c" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions_019ecbb3-bd2e-705b-8f31-5342089462cd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019ecbb3-bd2e-76f2-8110-55dae9b8e23c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_019ecbb3-bd2e-7c45-b591-5fbd8e456f4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RealizedInvestmentGainsLosses"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019ecbb3-bd2e-76f2-8110-55dae9b8e23c" xlink:to="loc_us-gaap_RealizedInvestmentGainsLosses_019ecbb3-bd2e-7c45-b591-5fbd8e456f4d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionPriceChangeOperatingBeforeTax_019ecbb3-bd2e-7ce8-82ca-dadbb3ea29bf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionPriceChangeOperatingBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019ecbb3-bd2e-76f2-8110-55dae9b8e23c" xlink:to="loc_us-gaap_UnrealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionPriceChangeOperatingBeforeTax_019ecbb3-bd2e-7ce8-82ca-dadbb3ea29bf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeOperatingAfterExpenseAndTax_019ecbb3-bd2e-7e31-bebc-417f5f916db5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeOperatingAfterExpenseAndTax"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019ecbb3-bd2e-76f2-8110-55dae9b8e23c" xlink:to="loc_us-gaap_InvestmentIncomeOperatingAfterExpenseAndTax_019ecbb3-bd2e-7e31-bebc-417f5f916db5" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://owlrockcapitalcorporation.com/role/ConsolidatedStatementsofCashFlows" xlink:type="simple" xlink:href="ortf-20260630.xsd#ConsolidatedStatementsofCashFlows"/>
  <link:calculationLink xlink:role="http://owlrockcapitalcorporation.com/role/ConsolidatedStatementsofCashFlows" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6579-4389-718c-b1c5-cf55ec8feebe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfDebt_019e6579-4389-71f0-a216-72bf1ba7e392" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfDebt"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6579-4389-718c-b1c5-cf55ec8feebe" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfDebt_019e6579-4389-71f0-a216-72bf1ba7e392" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfDebt_019e6579-4389-79c9-b6f8-586c6905f7da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfDebt"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6579-4389-718c-b1c5-cf55ec8feebe" xlink:to="loc_us-gaap_RepaymentsOfDebt_019e6579-4389-79c9-b6f8-586c6905f7da" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019e6579-4389-7747-a209-db2d4566b34f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6579-4389-718c-b1c5-cf55ec8feebe" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019e6579-4389-7747-a209-db2d4566b34f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019e6579-4389-7bf3-8991-2dfa8fe09c3f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6579-4389-718c-b1c5-cf55ec8feebe" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019e6579-4389-7bf3-8991-2dfa8fe09c3f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsCommonStock_019e6579-4389-73e6-9031-18f95ca719b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDividendsCommonStock"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6579-4389-718c-b1c5-cf55ec8feebe" xlink:to="loc_us-gaap_PaymentsOfDividendsCommonStock_019e6579-4389-73e6-9031-18f95ca719b5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e6579-4389-7210-9e26-191b360c4aa2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_NetIncomeLoss_019e6579-4389-7210-9e26-191b360c4aa2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForPurchaseOfInvestmentOperatingActivity_019e6579-4389-7081-ba6b-df1aa71f11d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForPurchaseOfInvestmentOperatingActivity"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_PaymentsForPurchaseOfInvestmentOperatingActivity_019e6579-4389-7081-ba6b-df1aa71f11d2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDispositionOfInvestmentOperatingActivity_019e6579-4389-70d3-82ab-2ab9061049d4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromDispositionOfInvestmentOperatingActivity"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_ProceedsFromDispositionOfInvestmentOperatingActivity_019e6579-4389-70d3-82ab-2ab9061049d4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_019e6579-4389-7cf3-92a1-eb280c54a400" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_019e6579-4389-7cf3-92a1-eb280c54a400" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_019e6579-4389-71e8-89af-5db9363089b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_019e6579-4389-71e8-89af-5db9363089b9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnDerivatives_019e6579-4389-7328-b0f4-1bc3f565f02f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrealizedGainLossOnDerivatives"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_UnrealizedGainLossOnDerivatives_019e6579-4389-7328-b0f4-1bc3f565f02f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_UnrealizedGainLossOnForwardContracts_019e6579-4389-76af-9483-1603156dd575" xlink:href="ortf-20260630.xsd#ortf_UnrealizedGainLossOnForwardContracts"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_ortf_UnrealizedGainLossOnForwardContracts_019e6579-4389-76af-9483-1603156dd575" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_019e6579-4389-7318-bc5c-d1eb12fd45a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_019e6579-4389-7318-bc5c-d1eb12fd45a3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndEquitySecuritiesRealizedGainLoss_019e6579-4389-791b-aa15-7df974ed7953" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtAndEquitySecuritiesRealizedGainLoss"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_DebtAndEquitySecuritiesRealizedGainLoss_019e6579-4389-791b-aa15-7df974ed7953" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_ForeignCurrencyTransactionGainLossRealizedNoncash_019e6579-4389-7784-a29f-c642c3932aa3" xlink:href="ortf-20260630.xsd#ortf_ForeignCurrencyTransactionGainLossRealizedNoncash"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_ortf_ForeignCurrencyTransactionGainLossRealizedNoncash_019e6579-4389-7784-a29f-c642c3932aa3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_ForeignCurrencyTransactionGainLossRealizedDebt_019e6579-4389-7dd6-8b06-d33ec9f552f3" xlink:href="ortf-20260630.xsd#ortf_ForeignCurrencyTransactionGainLossRealizedDebt"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_ortf_ForeignCurrencyTransactionGainLossRealizedDebt_019e6579-4389-7dd6-8b06-d33ec9f552f3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_DividendAndInterestIncomeOperatingPaidInKind_019e6579-4389-7893-bfa8-7ffc820451c4" xlink:href="ortf-20260630.xsd#ortf_DividendAndInterestIncomeOperatingPaidInKind"/>
    <link:calculationArc order="12" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_ortf_DividendAndInterestIncomeOperatingPaidInKind_019e6579-4389-7893-bfa8-7ffc820451c4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_019e6579-4389-7c4f-9908-a580677abe2e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_019e6579-4389-7c4f-9908-a580677abe2e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_CashAcquiredInTheMergers_019e6579-4389-7b1f-9bdf-d169dff80078" xlink:href="ortf-20260630.xsd#ortf_CashAcquiredInTheMergers"/>
    <link:calculationArc order="14" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_ortf_CashAcquiredInTheMergers_019e6579-4389-7b1f-9bdf-d169dff80078" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInDividendsReceivable_019e6579-4389-7c6d-af6d-39f0f4422f7e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInDividendsReceivable"/>
    <link:calculationArc order="15" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_IncreaseDecreaseInDividendsReceivable_019e6579-4389-7c6d-af6d-39f0f4422f7e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019e6579-4389-7162-a41a-e57f1ca818d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:calculationArc order="16" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019e6579-4389-7162-a41a-e57f1ca818d2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInManagementFeePayable_019e6579-4389-735d-b2d1-e7eabe5c48ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInManagementFeePayable"/>
    <link:calculationArc order="17" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_IncreaseDecreaseInManagementFeePayable_019e6579-4389-735d-b2d1-e7eabe5c48ef" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInIncentiveFeePayable_019e6579-4389-7015-b682-388d4cd61126" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInIncentiveFeePayable"/>
    <link:calculationArc order="18" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_IncreaseDecreaseInIncentiveFeePayable_019e6579-4389-7015-b682-388d4cd61126" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInDueToAffiliates_019e6579-4389-78cc-ac9b-b10242ef47ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInDueToAffiliates"/>
    <link:calculationArc order="19" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_IncreaseDecreaseInDueToAffiliates_019e6579-4389-78cc-ac9b-b10242ef47ee" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPayableForInvestmentPurchased_019e6579-4389-73dd-bf40-eecd5e4fb27d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInPayableForInvestmentPurchased"/>
    <link:calculationArc order="20" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_IncreaseDecreaseInPayableForInvestmentPurchased_019e6579-4389-73dd-bf40-eecd5e4fb27d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_019e6579-4389-7410-b795-72dd0d2f1ed8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities"/>
    <link:calculationArc order="21" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7d46-8100-e0683197f07f" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_019e6579-4389-7410-b795-72dd0d2f1ed8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019e6579-4389-7adc-9705-9c015e8e8aa4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6579-4389-753d-ac45-dc3a9c4b3e1a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019e6579-4389-7adc-9705-9c015e8e8aa4" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6579-4389-753d-ac45-dc3a9c4b3e1a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7a71-81d0-2ee28ace33e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019e6579-4389-7adc-9705-9c015e8e8aa4" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6579-4389-7a71-81d0-2ee28ace33e5" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://owlrockcapitalcorporation.com/role/DebtScheduleofOutstandingDebtObligationsDetails" xlink:type="simple" xlink:href="ortf-20260630.xsd#DebtScheduleofOutstandingDebtObligationsDetails"/>
  <link:calculationLink xlink:role="http://owlrockcapitalcorporation.com/role/DebtScheduleofOutstandingDebtObligationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ortf_LineOfCreditFacilityRemainingBorrowingCapacityAndDebtInstrumentCapacityAmount_019e6579-444b-7619-8857-e638fc7e3815" xlink:href="ortf-20260630.xsd#ortf_LineOfCreditFacilityRemainingBorrowingCapacityAndDebtInstrumentCapacityAmount"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019e6579-444b-7371-a5cc-3679732eac29" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_LineOfCreditFacilityRemainingBorrowingCapacityAndDebtInstrumentCapacityAmount_019e6579-444b-7619-8857-e638fc7e3815" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019e6579-444b-7371-a5cc-3679732eac29" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_019e6579-444b-787e-a13f-a66d0cc5e552" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_LineOfCreditFacilityRemainingBorrowingCapacityAndDebtInstrumentCapacityAmount_019e6579-444b-7619-8857-e638fc7e3815" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_019e6579-444b-787e-a13f-a66d0cc5e552" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_LineOfCreditFacilityMaximumBorrowingCapacityAndDebtInstrumentFaceAmount_019e6579-444b-7ac1-90dc-1e63c3fbd687" xlink:href="ortf-20260630.xsd#ortf_LineOfCreditFacilityMaximumBorrowingCapacityAndDebtInstrumentFaceAmount"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019e6579-444b-771f-8cbc-f9c0ca075030" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_LineOfCreditFacilityMaximumBorrowingCapacityAndDebtInstrumentFaceAmount_019e6579-444b-7ac1-90dc-1e63c3fbd687" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019e6579-444b-771f-8cbc-f9c0ca075030" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019e6579-444b-74aa-ab6e-d34a2e6d65dd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_LineOfCreditFacilityMaximumBorrowingCapacityAndDebtInstrumentFaceAmount_019e6579-444b-7ac1-90dc-1e63c3fbd687" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019e6579-444b-74aa-ab6e-d34a2e6d65dd" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://owlrockcapitalcorporation.com/role/DebtScheduleofComponentsofInterestExpenseDetails" xlink:type="simple" xlink:href="ortf-20260630.xsd#DebtScheduleofComponentsofInterestExpenseDetails"/>
  <link:calculationLink xlink:role="http://owlrockcapitalcorporation.com/role/DebtScheduleofComponentsofInterestExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019e6579-444b-7040-8728-0361f0f5ab24" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1_019e6579-444b-7cbf-9f68-326b33d5f520" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseNonoperating_019e6579-444b-7040-8728-0361f0f5ab24" xlink:to="loc_us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1_019e6579-444b-7cbf-9f68-326b33d5f520" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_019e6579-444b-7213-905a-249a438c9463" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseNonoperating_019e6579-444b-7040-8728-0361f0f5ab24" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_019e6579-444b-7213-905a-249a438c9463" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_019e6579-444b-77a6-b2fb-e1a4d9e3eb13" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseDebt"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseNonoperating_019e6579-444b-7040-8728-0361f0f5ab24" xlink:to="loc_us-gaap_InterestExpenseDebt_019e6579-444b-77a6-b2fb-e1a4d9e3eb13" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://owlrockcapitalcorporation.com/role/DebtMaturityofDebtObligationsDetails" xlink:type="simple" xlink:href="ortf-20260630.xsd#DebtMaturityofDebtObligationsDetails"/>
  <link:calculationLink xlink:role="http://owlrockcapitalcorporation.com/role/DebtMaturityofDebtObligationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligation_019e6579-444b-7673-bab5-c13825f3c8fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractualObligation"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_ContractualObligationToBePaidLessThanOneYear_019e6579-444b-7eb9-b702-58c790a86c3a" xlink:href="ortf-20260630.xsd#ortf_ContractualObligationToBePaidLessThanOneYear"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ContractualObligation_019e6579-444b-7673-bab5-c13825f3c8fd" xlink:to="loc_ortf_ContractualObligationToBePaidLessThanOneYear_019e6579-444b-7eb9-b702-58c790a86c3a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_ContractualObligationToBePaidOneToThreeYears_019e6579-444b-7ea5-83d5-3309894cf8f8" xlink:href="ortf-20260630.xsd#ortf_ContractualObligationToBePaidOneToThreeYears"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ContractualObligation_019e6579-444b-7673-bab5-c13825f3c8fd" xlink:to="loc_ortf_ContractualObligationToBePaidOneToThreeYears_019e6579-444b-7ea5-83d5-3309894cf8f8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_ContractualObligationToBePaidThreeToFiveYears_019e6579-444b-7b46-bd03-aa46450ec1b6" xlink:href="ortf-20260630.xsd#ortf_ContractualObligationToBePaidThreeToFiveYears"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ContractualObligation_019e6579-444b-7673-bab5-c13825f3c8fd" xlink:to="loc_ortf_ContractualObligationToBePaidThreeToFiveYears_019e6579-444b-7b46-bd03-aa46450ec1b6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationDueAfterFifthYear_019e6579-444b-728e-bce1-440867974a88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractualObligationDueAfterFifthYear"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ContractualObligation_019e6579-444b-7673-bab5-c13825f3c8fd" xlink:to="loc_us-gaap_ContractualObligationDueAfterFifthYear_019e6579-444b-728e-bce1-440867974a88" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://owlrockcapitalcorporation.com/role/FinancialHighlightsDetails" xlink:type="simple" xlink:href="ortf-20260630.xsd#FinancialHighlightsDetails"/>
  <link:calculationLink xlink:role="http://owlrockcapitalcorporation.com/role/FinancialHighlightsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyNetAssetValuePerSharePeriodIncreaseDecrease_019e6579-444b-7e49-b6f5-e58e0f6d3426" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyNetAssetValuePerSharePeriodIncreaseDecrease"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShare_019e6579-444b-7bdc-8ba0-1c31a07d4c26" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShare"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentCompanyNetAssetValuePerSharePeriodIncreaseDecrease_019e6579-444b-7e49-b6f5-e58e0f6d3426" xlink:to="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShare_019e6579-444b-7bdc-8ba0-1c31a07d4c26" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyDistributionToShareholdersPerShare_019e6579-444b-7b84-b41e-0e7bb6103c2b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyDistributionToShareholdersPerShare"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentCompanyNetAssetValuePerSharePeriodIncreaseDecrease_019e6579-444b-7e49-b6f5-e58e0f6d3426" xlink:to="loc_us-gaap_InvestmentCompanyDistributionToShareholdersPerShare_019e6579-444b-7b84-b41e-0e7bb6103c2b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_InvestmentCompanyRepurchaseOfCommonSharesPerShare_019e6579-444b-715f-87c5-73c587382e68" xlink:href="ortf-20260630.xsd#ortf_InvestmentCompanyRepurchaseOfCommonSharesPerShare"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentCompanyNetAssetValuePerSharePeriodIncreaseDecrease_019e6579-444b-7e49-b6f5-e58e0f6d3426" xlink:to="loc_ortf_InvestmentCompanyRepurchaseOfCommonSharesPerShare_019e6579-444b-715f-87c5-73c587382e68" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_InvestmentCompanyIssuanceOfCommonStockPerShare_019e6579-444b-7d4c-840f-c0514eb03128" xlink:href="ortf-20260630.xsd#ortf_InvestmentCompanyIssuanceOfCommonStockPerShare"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentCompanyNetAssetValuePerSharePeriodIncreaseDecrease_019e6579-444b-7e49-b6f5-e58e0f6d3426" xlink:to="loc_ortf_InvestmentCompanyIssuanceOfCommonStockPerShare_019e6579-444b-7d4c-840f-c0514eb03128" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShare_019e6579-444b-71b8-883a-68c97e90895b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShare"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyGainLossOnInvestmentPerShare_019e6579-444b-7232-9c1d-2605c8621984" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyGainLossOnInvestmentPerShare"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShare_019e6579-444b-71b8-883a-68c97e90895b" xlink:to="loc_us-gaap_InvestmentCompanyGainLossOnInvestmentPerShare_019e6579-444b-7232-9c1d-2605c8621984" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossPerShare_019e6579-444b-7a3b-829b-194051d07592" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyInvestmentIncomeLossPerShare"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShare_019e6579-444b-71b8-883a-68c97e90895b" xlink:to="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossPerShare_019e6579-444b-7a3b-829b-194051d07592" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://owlrockcapitalcorporation.com/role/MergerwithBlueOwlTechnologyFinanceCorpIIAllocationofPurchasePriceDetails" xlink:type="simple" xlink:href="ortf-20260630.xsd#MergerwithBlueOwlTechnologyFinanceCorpIIAllocationofPurchasePriceDetails"/>
  <link:calculationLink xlink:role="http://owlrockcapitalcorporation.com/role/MergerwithBlueOwlTechnologyFinanceCorpIIAllocationofPurchasePriceDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionConsiderationTransferred_019e6579-444b-7224-bf4e-8c1e4a59f5a2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionConsiderationTransferred"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionConsiderationTransferredEquityInterestIssuedAndIssuable_019e6579-444b-705d-8b5b-d5419e24ebf0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionConsiderationTransferredEquityInterestIssuedAndIssuable"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetAcquisitionConsiderationTransferred_019e6579-444b-7224-bf4e-8c1e4a59f5a2" xlink:to="loc_us-gaap_AssetAcquisitionConsiderationTransferredEquityInterestIssuedAndIssuable_019e6579-444b-705d-8b5b-d5419e24ebf0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionConsiderationTransferredTransactionCost_019e6579-444b-7369-819f-85be85a36aa7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionConsiderationTransferredTransactionCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetAcquisitionConsiderationTransferred_019e6579-444b-7224-bf4e-8c1e4a59f5a2" xlink:to="loc_us-gaap_AssetAcquisitionConsiderationTransferredTransactionCost_019e6579-444b-7369-819f-85be85a36aa7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionPurchasePremiumDiscount_019e6579-444b-7e8a-9e03-a6fdbd4356d1" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionPurchasePremiumDiscount"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionAssetsAcquiredAndLiabilitiesAssumedNet_019e6579-444b-79d2-bd9d-770aec01dbe5" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionAssetsAcquiredAndLiabilitiesAssumedNet"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_AssetAcquisitionPurchasePremiumDiscount_019e6579-444b-7e8a-9e03-a6fdbd4356d1" xlink:to="loc_ortf_AssetAcquisitionAssetsAcquiredAndLiabilitiesAssumedNet_019e6579-444b-79d2-bd9d-770aec01dbe5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionConsiderationTransferred_019e6579-444b-7bf8-99dd-0d0d97838ce8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionConsiderationTransferred"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_AssetAcquisitionPurchasePremiumDiscount_019e6579-444b-7e8a-9e03-a6fdbd4356d1" xlink:to="loc_us-gaap_AssetAcquisitionConsiderationTransferred_019e6579-444b-7bf8-99dd-0d0d97838ce8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionLiabilities_019e6579-444b-7200-baf6-02e141faa1a2" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionLiabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionOtherLiabilities_019e6579-444b-74ea-b0ea-8ccfcd87b44c" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionOtherLiabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_AssetAcquisitionLiabilities_019e6579-444b-7200-baf6-02e141faa1a2" xlink:to="loc_ortf_AssetAcquisitionOtherLiabilities_019e6579-444b-74ea-b0ea-8ccfcd87b44c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionLongTermDebt_019e6579-444b-7cd5-b9eb-44e4f0528f38" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionLongTermDebt"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_AssetAcquisitionLiabilities_019e6579-444b-7200-baf6-02e141faa1a2" xlink:to="loc_ortf_AssetAcquisitionLongTermDebt_019e6579-444b-7cd5-b9eb-44e4f0528f38" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionAssetsAcquiredAndLiabilitiesAssumedNet_019e6579-444b-7acc-8525-6b5bb7e95436" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionAssetsAcquiredAndLiabilitiesAssumedNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionAssets_019e6579-444b-7a39-9890-3ea72e4f4a56" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionAssets"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_AssetAcquisitionAssetsAcquiredAndLiabilitiesAssumedNet_019e6579-444b-7acc-8525-6b5bb7e95436" xlink:to="loc_ortf_AssetAcquisitionAssets_019e6579-444b-7a39-9890-3ea72e4f4a56" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionLiabilities_019e6579-444b-744c-b278-bad92fceaf53" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionLiabilities"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_AssetAcquisitionAssetsAcquiredAndLiabilitiesAssumedNet_019e6579-444b-7acc-8525-6b5bb7e95436" xlink:to="loc_ortf_AssetAcquisitionLiabilities_019e6579-444b-744c-b278-bad92fceaf53" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionAssets_019e6579-444b-75d3-a723-57f3e1c77886" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionAssets"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionInterestReceivable_019e6579-444b-77c9-8cb0-b5ecdf887920" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionInterestReceivable"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_AssetAcquisitionAssets_019e6579-444b-75d3-a723-57f3e1c77886" xlink:to="loc_ortf_AssetAcquisitionInterestReceivable_019e6579-444b-77c9-8cb0-b5ecdf887920" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionCashAndEquivalents_019e6579-444b-70e7-976d-58b37f34f261" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionCashAndEquivalents"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_AssetAcquisitionAssets_019e6579-444b-75d3-a723-57f3e1c77886" xlink:to="loc_ortf_AssetAcquisitionCashAndEquivalents_019e6579-444b-70e7-976d-58b37f34f261" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionInvestmentsFairValue_019e6579-444b-72f5-a8ef-a858739c96af" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionInvestmentsFairValue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_AssetAcquisitionAssets_019e6579-444b-75d3-a723-57f3e1c77886" xlink:to="loc_ortf_AssetAcquisitionInvestmentsFairValue_019e6579-444b-72f5-a8ef-a858739c96af" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ortf_AssetAcquisitionOtherAssets_019e6579-444b-759e-9467-4ad5841100ec" xlink:href="ortf-20260630.xsd#ortf_AssetAcquisitionOtherAssets"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ortf_AssetAcquisitionAssets_019e6579-444b-75d3-a723-57f3e1c77886" xlink:to="loc_ortf_AssetAcquisitionOtherAssets_019e6579-444b-759e-9467-4ad5841100ec" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
