Interest on a money judgment.
Prejudgment interest runs from the day the cause of action arose. Postjudgment interest runs from the day of the order. The rate is fixed by the quarter, not by today, and the Ministry of the Attorney General publishes it. This works out both.
Interest you can add to the claim
Put in what you are owed and the dates, and this works out the interest you can add to your claim.
Section 130 lets the court change all of this. It may disallow interest, change the rate, or change the period. A different rate also applies if your contract sets one, if a statute sets one, or if the claim is for non-pecuniary damages in a personal injury action, where rule 53.10 of the Rules of Civil Procedure governs. And you only get prejudgment interest if you claimed it: if it is not in your plaintiff’s claim, it is not in the judgment.
Rates from the table the Ministry of the Attorney General publishes under section 127(2) of the Courts of Justice Act. Rates last checked 2 June 2026.
What this calculator does not do
- Apply the exclusions in section 128(4). No prejudgment interest runs on punitive damages, on interest itself, on costs, on pecuniary loss arising after the order, on the amount of an advance payment for the period after it was made, or on an order made on consent unless the debtor consented.
- Apply the six-month rests in section 128(3), which calculate interest on past pecuniary loss on the running total at the end of each six-month period.
- Use the rule 53.10 rate for non-pecuniary damages in a personal injury action, which section 128(2) requires instead of the section 127 rate.
- Account for a partial payment. Interest stops running on money that has been paid, so a judgment paid down in stages needs the calculation split at each payment date, exactly as the Ministry's own worked example does.
- Decide entitlement. Section 130 gives the court a discretion to disallow interest entirely.
This calculator applies sections 127 to 129 of the Courts of Justice Act using the interest rate tables the Ministry of the Attorney General publishes. It assumes simple interest at the statutory rate, with no contract rate and no other statute in play. It does not apply the exclusions in section 128(4), the six-month rests for past pecuniary loss in section 128(3), or the court's discretion under section 130. It is an estimate for orientation, not a calculation you can file.
Interest is worth having and it is easy to lose: if you do not claim it in your plaintiff’s claim, the judgment will not include it. That is the point at which a half-hour with Telesh Law Firm Professional Corp pays for itself.