Ontario Postjudgment Interest Calculator (2026)
Postjudgment interest under s. 129 of the Courts of Justice Act, with a full breakdown when partial payments are made.
Ontario Postjudgment Interest Calculator (s. 129 CJA)
Version 4.000 – Last updated on July 20, 2026.
Partial Payments
OptionalIf you (or the other side) made partial payments before the Full Payment Date, add them here, including the payment amount in the first box and the payment date in the second box. Leave empty if paid in full at once.
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2026 Ontario Postjudgment Interest Rates
The quarterly postjudgment interest rate set under section 129 of the Courts of Justice Act, with the prejudgment rate alongside for comparison. Q4 is published by the Ministry of the Attorney General closer to the quarter.
Historical Ontario interest rates by quarter
The full official quarterly series. Prejudgment rates apply to causes of action arising after October 23, 1989; the postjudgment column also serves as the prejudgment rate for causes of action arising on or before that date. Find your rate by the quarter your proceeding was commenced (prejudgment) or the quarter the order was made (postjudgment).
Show the full rate table (2000 to present)
| Quarter | Prejudgment | Postjudgment |
|---|---|---|
| Q3 2026 (Jul–Sep) | 2.5% | 4.0% |
| Q2 2026 (Apr–Jun) | 2.5% | 4.0% |
| Q1 2026 (Jan–Mar) | 2.5% | 4.0% |
| Q4 2025 (Oct–Dec) | 3.0% | 4.0% |
| Q3 2025 (Jul–Sep) | 3.0% | 4.0% |
| Q2 2025 (Apr–Jun) | 3.3% | 5.0% |
| Q1 2025 (Jan–Mar) | 4.0% | 5.0% |
| Q4 2024 (Oct–Dec) | 4.8% | 6.0% |
| Q3 2024 (Jul–Sep) | 5.3% | 7.0% |
| Q2 2024 (Apr–Jun) | 5.3% | 7.0% |
| Q1 2024 (Jan–Mar) | 5.3% | 7.0% |
| Q4 2023 (Oct–Dec) | 5.3% | 7.0% |
| Q3 2023 (Jul–Sep) | 4.8% | 6.0% |
| Q2 2023 (Apr–Jun) | 4.8% | 6.0% |
| Q1 2023 (Jan–Mar) | 4.0% | 5.0% |
| Q4 2022 (Oct–Dec) | 2.8% | 4.0% |
| Q3 2022 (Jul–Sep) | 1.8% | 3.0% |
| Q2 2022 (Apr–Jun) | 0.5% | 2.0% |
| Q1 2022 (Jan–Mar) | 0.5% | 2.0% |
| Q4 2021 (Oct–Dec) | 0.5% | 2.0% |
| Q3 2021 (Jul–Sep) | 0.5% | 2.0% |
| Q2 2021 (Apr–Jun) | 0.5% | 2.0% |
| Q1 2021 (Jan–Mar) | 0.5% | 2.0% |
| Q4 2020 (Oct–Dec) | 0.5% | 2.0% |
| Q3 2020 (Jul–Sep) | 0.5% | 2.0% |
| Q2 2020 (Apr–Jun) | 2.0% | 3.0% |
| Q1 2020 (Jan–Mar) | 2.0% | 3.0% |
| Q4 2019 (Oct–Dec) | 2.0% | 3.0% |
| Q3 2019 (Jul–Sep) | 2.0% | 3.0% |
| Q2 2019 (Apr–Jun) | 2.0% | 3.0% |
| Q1 2019 (Jan–Mar) | 2.0% | 3.0% |
| Q4 2018 (Oct–Dec) | 1.8% | 3.0% |
| Q3 2018 (Jul–Sep) | 1.5% | 3.0% |
| Q2 2018 (Apr–Jun) | 1.5% | 3.0% |
| Q1 2018 (Jan–Mar) | 1.3% | 3.0% |
| Q4 2017 (Oct–Dec) | 1.0% | 2.0% |
| Q3 2017 (Jul–Sep) | 0.8% | 2.0% |
| Q2 2017 (Apr–Jun) | 0.8% | 2.0% |
| Q1 2017 (Jan–Mar) | 0.8% | 2.0% |
| Q4 2016 (Oct–Dec) | 0.8% | 2.0% |
| Q3 2016 (Jul–Sep) | 0.8% | 2.0% |
| Q2 2016 (Apr–Jun) | 0.8% | 2.0% |
| Q1 2016 (Jan–Mar) | 0.8% | 2.0% |
| Q4 2015 (Oct–Dec) | 1.0% | 2.0% |
| Q3 2015 (Jul–Sep) | 1.0% | 2.0% |
| Q2 2015 (Apr–Jun) | 1.0% | 2.0% |
| Q1 2015 (Jan–Mar) | 1.3% | 3.0% |
| Q4 2014 (Oct–Dec) | 1.3% | 3.0% |
| Q3 2014 (Jul–Sep) | 1.3% | 3.0% |
| Q2 2014 (Apr–Jun) | 1.3% | 3.0% |
| Q1 2014 (Jan–Mar) | 1.3% | 3.0% |
| 2013 (all quarters) | 1.3% | 3.0% |
| 2012 (all quarters) | 1.3% | 3.0% |
| 2011 (all quarters) | 1.3% | 3.0% |
| Q4 2010 (Oct–Dec) | 1.0% | 2.0% |
| Q3 2010 (Jul–Sep) | 0.8% | 2.0% |
| Q2 2010 (Apr–Jun) | 0.5% | 2.0% |
| Q1 2010 (Jan–Mar) | 0.5% | 2.0% |
| Q4 2009 (Oct–Dec) | 0.5% | 2.0% |
| Q3 2009 (Jul–Sep) | 0.5% | 2.0% |
| Q2 2009 (Apr–Jun) | 1.3% | 3.0% |
| Q1 2009 (Jan–Mar) | 2.5% | 4.0% |
| Q4 2008 (Oct–Dec) | 3.3% | 5.0% |
| Q3 2008 (Jul–Sep) | 3.3% | 5.0% |
| Q2 2008 (Apr–Jun) | 4.3% | 6.0% |
| Q1 2008 (Jan–Mar) | 4.8% | 6.0% |
| Q4 2007 (Oct–Dec) | 4.8% | 6.0% |
| Q3 2007 (Jul–Sep) | 4.5% | 6.0% |
| Q2 2007 (Apr–Jun) | 4.5% | 6.0% |
| Q1 2007 (Jan–Mar) | 4.5% | 6.0% |
| Q4 2006 (Oct–Dec) | 4.5% | 6.0% |
| Q3 2006 (Jul–Sep) | 4.5% | 6.0% |
| Q2 2006 (Apr–Jun) | 3.8% | 5.0% |
| Q1 2006 (Jan–Mar) | 3.3% | 5.0% |
| 2005 (all quarters) | 2.8% | 4.0% |
| Q4 2004 (Oct–Dec) | 2.3% | 4.0% |
| Q3 2004 (Jul–Sep) | 2.3% | 4.0% |
| Q2 2004 (Apr–Jun) | 2.8% | 4.0% |
| Q1 2004 (Jan–Mar) | 3.0% | 4.0% |
| Q4 2003 (Oct–Dec) | 3.3% | 5.0% |
| Q3 2003 (Jul–Sep) | 3.5% | 5.0% |
| Q2 2003 (Apr–Jun) | 3.0% | 4.0% |
| Q1 2003 (Jan–Mar) | 3.0% | 4.0% |
| Q4 2002 (Oct–Dec) | 3.0% | 4.0% |
| Q3 2002 (Jul–Sep) | 2.5% | 4.0% |
| Q2 2002 (Apr–Jun) | 2.3% | 4.0% |
| Q1 2002 (Jan–Mar) | 2.5% | 4.0% |
| Q4 2001 (Oct–Dec) | 4.3% | 6.0% |
| Q3 2001 (Jul–Sep) | 4.8% | 6.0% |
| Q2 2001 (Apr–Jun) | 5.8% | 7.0% |
| Q1 2001 (Jan–Mar) | 6.0% | 7.0% |
| Q4 2000 (Oct–Dec) | 6.0% | 7.0% |
| Q3 2000 (Jul–Sep) | 6.0% | 7.0% |
| Q2 2000 (Apr–Jun) | 5.3% | 7.0% |
| Q1 2000 (Jan–Mar) | 5.0% | 6.0% |
Rates are listed by quarter. A few quiet years where every quarter held the same rate are shown as a single row. The complete official series back to 1985, and the prime-bank-rate rules for proceedings before 1985, are published by the Ministry. Always confirm the exact rate for your quarter against the official source before relying on it.
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Ontario Postjudgment Interest Calculator
Courtready's Ontario Postjudgment Interest Calculator works out postjudgment interest under section 129 of the Courts of Justice Act, using the statutory quarterly rate tables published by the Government of Ontario. The rate is set by the quarter the order was made and holds until the judgment is paid off. Interest accrues on the amount ordered plus costs plus any prejudgment interest, and where partial payments are made along the way, the calculator splits the timeline at every payment date and shows a full period by period breakdown. Check out our other free tools below.
Two things to get right before you rely on the number. First, enter the combined figure in step 1: the award, the costs as ordered, and the prejudgment interest together, because that is the amount section 129 interest runs on. Second, the interest is simple, never compounding, unless a contract pleaded in the claim provides otherwise or a court exercises its discretion under section 130. The same rules apply in Small Claims Court, which sits within the Superior Court of Justice. For the period before the order, use our free Ontario Prejudgment Interest Calculator.
Disclaimer: This tool is provided for reference purposes only and does not constitute legal advice. Always verify the applicable rate against the Government of Ontario published rates and the current version of the Courts of Justice Act. Maintained by Tom Macintosh Zheng, co-founder of Courtready.ca and a licensed lawyer in Ontario; last reviewed and updated in July 2026. For questions or to report an error, please email admin [at] courtready.ca.
Common Questions
What is the Ontario postjudgment interest rate in 2026?
For orders made in 2026, the Ontario postjudgment interest rate under section 129 of the Courts of Justice Act is 4.0%. It has held at 4.0% for every quarter published so far (Q1 through Q3). The rates are set quarterly by the Ministry of the Attorney General and published by the Government of Ontario; the Q4 rate is published closer to the quarter.
Which quarter's rate applies to my judgment?
The quarter in which the order was made. That rate then stays fixed until the judgment is paid off, even if payment stretches across multiple quarters or years. The rate does not float with later quarterly updates.
What amount does postjudgment interest run on?
Postjudgment interest accrues on the full amount the court orders: the award itself, plus costs as ordered, plus any prejudgment interest. That combined figure is what you should enter in the calculator. Interest runs from the date of the order to the date of payment.
How do partial payments affect postjudgment interest?
Each partial payment reduces the balance that interest accrues on from the date of that payment forward. The correct approach is to calculate interest separately for each period on the unpaid balance at the time. This calculator does that automatically and shows a full period by period breakdown of the math.
How is Ontario postjudgment interest calculated?
Ontario postjudgment interest is calculated under section 129 of the Courts of Justice Act. For each period, the formula is: unpaid balance × rate% ÷ 365 × number of days in the period. Where no partial payments are made, that is a single period from the order date to the payment date.
Is postjudgment interest simple or compound?
It is simple interest, so it never builds on interest that has already accrued. Compounding only enters the picture where a contract pleaded in the claim calls for it, or in the narrow situations where a court uses its discretion under section 130 of the Courts of Justice Act.
What about interest before the judgment?
Interest for the period before the order is prejudgment interest under section 128, which runs from the date the cause of action arose to the date of the order at a separate quarterly rate. Use our free Ontario Prejudgment Interest Calculator for that calculation.
Is this Ontario postjudgment interest calculator free to use?
Yes. The calculator is completely free, with no account, login, or payment required. It is provided by Courtready as a public legal education resource. It is a reference tool only and does not constitute legal advice. Always verify the applicable rate against the Government of Ontario published rate tables and the current version of the Courts of Justice Act.
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