How this instrument works
A money judgment does not freeze in place once a court signs it. Nearly every U.S. jurisdiction lets the amount keep growing while it goes unpaid, at a post-judgment interest rate the legislature or the court sets — sometimes a flat figure like 9% or 10%, sometimes a rate pegged to a Treasury yield or the prime rate and reset on a schedule. That growing balance is what this instrument computes: the extra dollars owed on top of the original award, purely from the passage of time.
The formula is deliberately plain — judgment times rate times years — because most judgment-interest statutes specify simple interest, not compounding. The award earns interest on its original face value for as long as it remains unpaid; the interest itself does not then start earning further interest. That single design choice is why a debtor's payoff figure grows in a straight line rather than curving upward the way a compounding loan balance would.
The number this instrument returns assumes the full judgment sat unpaid for the entire span you enter, at one constant rate. It cannot know your state's actual statutory rate, whether a partial payment landed partway through, or whether the judgment already folds in prejudgment interest, court costs, or awarded attorney's fees. Treat the result as the arithmetic of one rate over one stretch of time, and verify the inputs against the judgment document and the statute that governs it before relying on the payoff figure.
- Enter the "Judgment amount, $" — the principal sum the court actually awarded, before any interest.
- Enter the "Post-judgment interest rate, %" — the statutory or court-ordered annual rate that applies in your jurisdiction.
- Enter "Years since judgment" — how long the award has gone unpaid, in years; use a decimal such as 1.5 for eighteen months.
- Read "Interest owed, $" — the amount that has accrued on top of the original judgment at that rate for that stretch of time.
Worked example — a $50,000 award at 9% for two years
A creditor holds a $50,000 money judgment against a debtor who has made no payment. The state sets a statutory post-judgment rate of 9% a year, a common fixed figure among the states that use a flat rate rather than a floating one, and two full years pass before any money arrives. The arithmetic is $50,000 times 9% times 2, which is $9,000 in accrued interest — exactly the golden case this instrument is built to reproduce: judgmentAmount 50000, annualRate 9, years 2, interestOwed 9000.
To satisfy the judgment in full at that moment, the debtor now owes $59,000 — the original $50,000 plus the $9,000 that accrued while it sat unpaid. Because the interest is simple rather than compounding, that $9,000 does not itself begin generating further interest; each additional year adds another flat $4,500 (9% of the original $50,000) until the balance is paid or the rate changes by statute.
Questions
Is post-judgment interest simple or compound?
Simple, in nearly every U.S. state. The interest is judgment amount times rate times years, calculated once against the original award for however long it remains unpaid — it does not compound onto itself. Federal court judgments follow a different mechanism, a rate set weekly under 28 U.S.C. § 1961, so confirm which rule actually governs your case before relying on this figure.
Where does the interest rate actually come from?
From statute, not from negotiation between the parties. Many states fix a flat annual rate, commonly 9% or 10%, while others peg the rate to a benchmark such as the one-year Treasury yield or the prime rate and reset it periodically. The rate that actually applies to your judgment is usually printed on the judgment itself or set out in that state's code of civil procedure — enter that figure rather than an assumed one.
Does the interest clock start at judgment or at the original claim?
Post-judgment interest starts on the date the court enters judgment, not on the date the underlying dispute began. Interest that accrued before that point is a separate calculation called prejudgment interest, often at a different rate, and it is typically folded into the principal before this clock starts running. Check the judgment's language for whether prejudgment interest is already included in the amount you enter here.
What if the debtor made a partial payment partway through?
This instrument assumes the full judgment amount stayed unpaid for the entire period you enter, so a partial payment changes the true figure. The correct approach is to run the calculation twice — once at the original balance for the time before the payment, once at the reduced balance for the time after — and add the two interest amounts together for the real total.
Can a debtor use this to plan a payoff amount?
Yes, to see the arithmetic: enter the judgment amount, the jurisdiction's statutory rate, and the years elapsed to find how much interest has accrued on top of the award. It shows the calculation only — it does not account for a negotiated settlement discount, a payment plan, or added collection costs, so confirm the final payoff figure against the court file or the creditor's attorney before paying.
Does this include court costs, fees, or collection expenses?
No. This figure is interest on the judgment principal alone. Filing fees, attorney's fees awarded as part of the judgment, and collection costs such as garnishment or lien-filing fees are separate line items, and some jurisdictions let those also accrue interest — check the judgment and local court rules before treating this number as the entire amount due.
References
Read this first: This instrument shows arithmetic, not advice. Real offers add fees, taxes and terms that vary by lender and place — verify the figures against your actual paperwork before deciding anything.