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Ontario Small Claims Court Postjudgment Interest Calculator

Calculate post-judgment interest under the Courts of Justice Act, s. 129 using the official rate for the quarter the order was made — from the date of judgment to the date of payment.

For estimation purposes only. Not legal advice. Confirm rates with the Ontario Ministry of the Attorney General.
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Calculate Interest on an Unpaid Judgment

Judgment Details
Interest Rate

The official CJA s. 129 rate for the quarter the order was made will be applied automatically — a single rate for the whole period.

Results
Enter your judgment details and click Calculate Interest to see a full breakdown.
Quick Answer

In Ontario, post-judgment interest runs on the unpaid amount of a judgment from the date of the order until it is paid in full. Unless a contract or statute sets a different rate, it uses the rate published quarterly under section 129 of the Courts of Justice Act for the quarter in which the judgment was given. It accrues automatically — no separate application is needed — and keeps building while you take enforcement steps to collect.

Courts of Justice Act — Quarterly Post-Judgment Interest Rates (s. 129)% per annum
YearQ1 (Jan–Mar)Q2 (Apr–Jun)Q3 (Jul–Sep)Q4 (Oct–Dec)
20264.00%4.00%4.00%4.00%
20255.00%5.00%4.00%4.00%
20247.00%7.00%7.00%6.00%
20237.00%7.00%7.00%7.00%
20220.50%1.50%3.50%4.50%
20210.50%0.50%0.50%0.50%
20202.50%0.50%0.50%0.50%
20192.00%2.00%2.00%2.00%
20181.50%1.50%1.50%2.00%
20171.00%1.00%1.50%1.50%
20161.00%1.00%1.00%1.00%
20151.00%1.00%1.00%1.00%
20141.00%1.00%1.00%1.00%
20131.00%1.00%1.00%1.00%
20121.50%1.50%1.00%1.00%
20111.50%1.50%1.50%1.50%
20101.00%1.50%1.50%1.50%
20091.50%1.00%1.00%1.00%
20084.50%4.00%3.50%2.50%
20074.50%4.50%4.50%4.50%
20063.50%4.00%4.00%4.00%
20052.50%2.50%2.50%3.00%
20043.50%3.50%3.50%3.50%
20033.00%3.50%3.50%3.50%
20023.00%3.00%3.00%3.00%
20016.50%6.50%5.50%4.50%
20006.00%6.00%6.00%6.00%
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Courts of Justice Act s. 129

Post-judgment interest accrues from the date of judgment under s. 129 of the Courts of Justice Act, at the rate for the quarter the order was made — published in the Ministry of the Attorney General's official rate tables.

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Simple Interest Only

Post-judgment interest is simple, not compound. It is calculated per day on the outstanding judgment amount.

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Valid for 20 Years

An Ontario judgment is valid and enforceable for 20 years. Interest continues to accrue until the judgment is paid in full.

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Enforcement Tools

Collect your judgment plus accrued interest through wage garnishment, bank garnishment, or a writ of seizure and sale.

What Is Postjudgment Interest?

Postjudgment interest is the interest that accumulates on the unpaid amount of a judgment from the date the order is made until the debtor pays in full. In Ontario it is governed by section 129 of the Courts of Justice Act and accrues automatically — you do not need to apply for it, and it keeps building while you take enforcement steps.

It is the counterpart to prejudgment interest, which compensates you for the period before judgment. Once a Small Claims Court judgment is granted, prejudgment interest stops and postjudgment interest takes over on the full amount of the order, including awarded costs.

How Postjudgment Interest Is Calculated in Ontario

Postjudgment interest is simple interest, calculated as:

Interest = Unpaid Judgment × Rate × (Days ÷ 365)

The rate is the postjudgment interest rate published for the quarter in which the judgment was given, and that single rate applies for as long as the judgment stays unpaid — it does not reset each quarter. If the debtor makes partial payments, interest continues only on the remaining balance. A contract that sets its own post-default rate can displace the statutory rate.

When Does Postjudgment Interest Begin?

It begins on the date of the order — the day the judge grants judgment or a default judgment is signed — not the day you start enforcement. From that day forward the unpaid amount earns interest daily until it is fully paid, and an Ontario judgment remains enforceable for 20 years, with interest accruing the entire time.

Postjudgment Interest Calculation Example

Suppose a plaintiff obtains a $15,000 Small Claims Court judgment in Q1 2026, when the postjudgment rate is 4.0% per year, and the defendant still has not paid 180 days later:

$15,000 × 4.0% × (180 ÷ 365) = $295.89

The debtor now owes roughly $15,295.89, and the total keeps growing about $1.64 per day until payment. Exact amounts are confirmed at the time of payment or enforcement, so treat the calculator's output as an estimate.

Enforcing an Unpaid Small Claims Court Judgment

A judgment is not a payment — if the debtor ignores it, you must enforce it. The main Small Claims Court enforcement tools are garnishment of wages or bank accounts, a writ of seizure and sale filed against the debtor's personal property or land, and an examination hearing that puts the debtor under oath about their income, assets and ability to pay. Enforcement filing fees are themselves recoverable and added to the judgment debt.

Postjudgment interest continues to accrue throughout enforcement, so a slow-paying debtor owes more the longer they wait. For a step-by-step walkthrough, see our guide on how to collect a judgment in Ontario.

Frequently Asked Questions

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