How to use the post-judgment interest calculator
A money judgment keeps growing until it is paid. Enter the judgment amount, the date it was entered, the date you are calculating through, and the annual rate that applies, and the calculator returns the days accrued, the interest, the running total, and how much is added each day.
Legal basis (as of September 2026) — for federal civil judgments, 28 U.S.C. §1961(a) sets interest at the weekly average one-year constant maturity Treasury yield for the week before the judgment, calculated daily and compounded annually under §1961(b). State judgments use their own statutory rates: California Code of Civil Procedure §685.010 sets 10% a year, and New York CPLR §5004 sets 9%, reduced to 2% for judgments on consumer debt.
Because the federal rate is republished weekly, the correct figure is the one in effect the week your judgment was entered, not today's. Prejudgment interest is a separate question governed by the underlying claim and often by state law, so it is not included here.
This calculator is for reference only and is not legal advice. Court clerks and judgment creditors may compute interest with slightly different day count conventions. Consult a licensed attorney about your specific judgment.
Frequently Asked Questions
Under 28 U.S.C. §1961(a) it is the weekly average one-year constant maturity Treasury yield for the calendar week preceding the judgment. The figure is published weekly, so use the one in effect when judgment was entered.
Federal judgments compound annually under §1961(b). Many states use simple interest at a fixed statutory rate instead, so check the rule in the court that entered your judgment.
No. Interest for the period before judgment depends on the underlying claim and on state law, and is calculated separately from the statutory post-judgment rate.