Judgment Interest Calculator

Estimate interest on a money judgment

Judgment interest is the interest that can accrue on a court-entered money judgment before it is paid. This calculator estimates simple interest between a judgment date and a payment date using the principal, annual rate, and day-count basis you enter. It is designed for budgeting, settlement discussions, and per-diem estimates, not for filing a final legal calculation without review.

Rates and compounding rules vary by jurisdiction, case type, and order language. For example, many U.S. federal civil and bankruptcy adversary judgments use rates governed by 28 U.S.C. 1961, while state judgments often follow state-specific statutes or court rules. Always confirm the correct rate, date from which interest begins, and whether interest is simple or compounded before relying on the result.

Formula used

The calculator uses a simple-interest estimate:

Interest = Principal × Annual Rate × (Days ÷ Day-count basis)

The principal is the judgment amount subject to interest. The annual rate is entered as a percentage, such as 6 for 6%. The days value is the calendar-day difference between the judgment date and payment date. The day-count basis is either 365 or 360 days, depending on the convention you select.

How to use the result

The output shows accrued interest, total owed, and per-diem interest. The per-diem value is often useful because it shows how much interest accrues for each additional day before payment. If the judgment is partly paid, rerun the calculation with the remaining principal and the appropriate new start date if your court rules require a reset.

Worked example

Suppose a $15,000 judgment accrues at 6% simple annual interest for 180 days on a 365-day basis. The estimate is $15,000 × 0.06 × (180 ÷ 365) = $443.84 of interest. The total payoff estimate is $15,443.84, and the daily per-diem interest is $15,000 × 0.06 ÷ 365 = $2.47.

What this calculator does not decide

• Whether interest is legally allowed on your judgment.
• Which statutory, contractual, or court-ordered rate applies.
• Whether interest compounds, changes over time, or pauses during appeal, bankruptcy, stay, or partial satisfaction.
• Whether costs, fees, sanctions, or prejudgment interest should also accrue interest.

Use the estimate as a worksheet. For legal enforcement, payoff letters, or court filings, verify the rule with the judgment, the clerk’s office, official court guidance, or qualified counsel.

When comparing settlement timing, run at least two scenarios: one through the expected payment date and another through a later fallback date. The gap between those totals shows the practical cost of delay and can help parties discuss payoff deadlines, escrow timing, or whether a partial payment meaningfully reduces future accrual.