Manitoba Prejudgment and Postjudgment Interest Calculator (2026)
Work out court interest under Part XIV of The Court of King’s Bench Act, at the quarterly rates published by the Court of King’s Bench.
In Manitoba one published rate serves both. The prejudgment rate is set by the quarter your claim was issued, and the postjudgment rate by the quarter judgment was given.
What kind of claim is this?
Your answer decides which day the interest clock starts on. Not sure? An unpaid bill or a loan is a set amount. An injury claim is not, because a judge has to work out what your loss is worth.
Pick one, so the calculator knows which start date to use.
Treat this answer as a rough guide
Two things about these claims are unsettled: what counts as putting your claim in writing (s. 80(1)(b)), and exactly how the six month blocks for past expenses work (s. 80(2)). We follow the words of the Act, but we could not find a Manitoba case deciding either point, so a court may see it differently. Use this to get a sense of where you stand, not as a number to rely on.
Does any of this apply to your case?
Section 80 does not apply to this claim
Section 82 switches off sections 79, 80 and 81, so there is no set rate for us to work out.
Two things still hold. If an agreement or another law provides for interest, or something in its place, that may still be payable, and this calculator cannot work it out for you. And section 82 says nothing about section 84, so postjudgment interest still runs on the order as usual, including on an order made by agreement.
The amount interest runs on
Interest runs on what the Act calls the principal sum. That is defined narrowly, so take out the amounts listed below before you enter a figure here.
The amount ordered, leaving out past expenses and lost income, pain and suffering, future losses, awards meant to punish, costs, and any MPIC reduction.Enter the principal sum, or 0 if the whole award is past expenses and lost income.
Pain and suffering earns no interest. Section 80(3) says so. Instead, when the judge sets that amount, they build in an allowance for the fact you could not invest the money in the meantime. It is inside the award rather than added on top. The rate still matters to that: under s. 80(4) the judge takes it into account.
Leave interest out. The principal sum does not include any interest awarded under the Act, so prejudgment interest never earns prejudgment interest on itself.
Costs work differently. Costs earn no prejudgment interest, but they do earn postjudgment interest under s. 84.
Dates
These three dates do different jobs. The first sets how long interest runs. The second sets the rate, and nothing else. They are often years apart, and that makes no difference to the rate.
Enter the start date.
Enter the day the court issued your claim.
Enter the date the order was made.
Examples of start dates
Special damages
Special damages are expenses you paid and income you lost before the order. Section 80(2) handles them separately. They are split into six month blocks counting from your notice date, and each block earns interest from its own first day up to the date of the order. So later blocks earn less.
A block cannot come out below zero once the MPIC reduction is taken off.
Does anything change the usual rate?
Section 84 applies unless one of these four things is true. It keeps applying even while the order is on hold or under appeal.
The usual Manitoba rate does not apply here
Something else sets the rate here, so this calculator cannot work out the figure.
What the judgment debt is made up of
Interest runs on the whole debt. When it comes to enforcing an order, s. 87 counts the prejudgment interest as part of the order, so it goes into the total here rather than sitting outside it.
How were the costs decided?
Enter a date on or after the day judgment was given.
Enter at least one amount, so there is something for interest to run on.
Dates
Interest runs from the day judgment was given, not the day the order was signed or served, and it keeps running through a hold or an appeal. That same day also fixes the rate for the whole period.
Enter the day judgment was given.
Enter a date on or after the day judgment was given.
Payments received
Add anything that has been paid since the order. Leave this empty if nothing has been paid.
Every payment needs a date on or after the order, and an amount above zero.
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Manitoba Prejudgment and Postjudgment Interest Calculator
This free Manitoba interest calculator works out both prejudgment interest and postjudgment interest under Part XIV of The Court of King’s Bench Act, C.C.S.M. c. C280, using the quarterly rates published by the Court of King’s Bench under s. 79(1). Manitoba works differently from Ontario and British Columbia: one published rate serves both regimes, and it is fixed at a single quarter rather than moving over the life of the claim. The prejudgment rate comes from the quarter your claim was issued, and the postjudgment rate from the quarter judgment was given. Check out our other free tools below.
Two things catch people out. First, because the rate is locked to a single quarter, a claim issued in 2021 or early 2022 still earns 0.50% a year even though the published rate later reached 5.00%, and s. 81 is the only route to something different. Second, s. 78 defines the principal sum narrowly: it leaves out special damages, pain and suffering, future losses, punitive damages, costs, and any reduction under the MPIC Act. Special damages have their own six month rule in s. 80(2), and pain and suffering earns no interest at all under s. 80(3). The calculator handles each of these separately and tells you which rule it has applied.
Rates are transcribed exactly as the Court of King’s Bench publishes them, and the published table currently reaches back to January 2014. If your claim was issued before then, the rate for that quarter is not published and you will need to ask the court registry. Where the Act leaves a question open, such as how a part payment is split between interest and the debt, the calculator says so on the result rather than presenting a convention as though it were a rule.
Disclaimer: This tool is provided for reference purposes only and does not constitute legal advice. Always verify the rate against the table published by the Court of King’s Bench, and check whether the Act your claim is based on sets its own rate. For questions or to report an error, please email admin [at] courtready.ca.
Common Questions
What is the prejudgment interest rate in Manitoba?
There is no single rate. The Court of King’s Bench publishes a rate for each quarter, and the one that applies to your claim is the rate for the quarter your claim was issued. That rate is then locked in for the whole period, however long the case takes. The published table currently runs from January 2014 to the current quarter, and the same table is used for both prejudgment and postjudgment interest.
Why has my rate not changed even though the published rate went up?
Because Manitoba fixes the rate at the quarter your claim was issued and leaves it there. Section 78 of The Court of King’s Bench Act defines the prejudgment rate as the quarterly rate for the quarter the proceeding was commenced. So a claim issued in early 2022, when the published rate was 0.50%, still earns 0.50% even though the rate reached 5.00% in 2024. If that produces an unfair result, s. 81 lets a judge set a different rate, and s. 81(2)(a) makes changes in the quarterly rate the first thing the judge must consider.
When does prejudgment interest start running in Manitoba?
It depends on the kind of claim. Where the amount was already fixed, such as a debt or an unpaid bill, interest runs from the day the cause of action arose under s. 80(1)(a). Where a judge had to work out the amount, such as a personal injury claim, interest runs from the day written notice of the claim was given to the person liable under s. 80(1)(b). The date your claim was issued does not affect this. It only sets the rate.
Do you get interest on pain and suffering in Manitoba?
No. Section 80(3) says no interest is awarded on non-pecuniary damages, which is the legal term for pain and suffering. Instead, when the judge sets that figure, they build in an allowance for the fact you could not invest the money in the meantime, so it sits inside the award rather than being added on top. Section 80(4) directs the judge to take the prejudgment rate into account when doing that. The Court of Appeal confirmed this reading in Lantin v Seven Oaks General Hospital, 2019 MBCA 115.
What is the postjudgment interest rate in Manitoba?
The rate for the quarter judgment was given, taken from the same published table as prejudgment interest, and fixed for as long as the judgment goes unpaid. Interest runs on the whole judgment debt, including costs, and it keeps running even while the order is on hold or under appeal, because s. 84(1) says so expressly. Section 87 counts prejudgment interest as part of the order for enforcement, so postjudgment interest runs on that too.
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