Legal Interest Calculator
Disclaimer: Post-judgment interest rates vary by jurisdiction. Enter the applicable statutory or contractual rate. Not legal advice.
A Judgment Doesn't Stop Accruing the Day It's Entered
Winning a judgment isn't the same as being paid — and most jurisdictions recognize that gap by allowing post-judgment interest to accrue on the unpaid balance until it's satisfied. That interest compensates the judgment creditor for the time value of money while collection is pending, and it's calculated using a simple daily-proration method rather than compounding, in most jurisdictions that apply a statutory rate.
The Formula
This is simple (non-compounding) interest prorated by the exact number of days between the judgment date and the as-of date, which is the standard method most jurisdictions use for statutory post-judgment interest.
Where This Matters
- Tracking a growing judgment balance — a judgment that sits unpaid for months or years accrues real additional interest, which matters when negotiating a payoff or settlement of the judgment itself.
- Calculating a current payoff figure — before accepting a settlement of an outstanding judgment, knowing the exact accrued interest as of today prevents underselling the total amount owed.
- Comparing statutory rates across jurisdictions — post-judgment interest rates differ by state and sometimes by year, so running the same principal and time period at different rates shows the practical impact of that variation.
| Days elapsed | Interest accrued | Total owed |
|---|---|---|
| 90 days | $221.92 | $10,221.92 |
| 180 days | $443.84 | $10,443.84 |
| 365 days | $900.00 | $10,900.00 |
How to Use This Calculator
- Enter the principal / judgment amount.
- Enter the annual interest rate as a percentage — the applicable statutory or contractual rate.
- Enter the judgment date.
- Enter an as-of date if calculating interest as of a date other than today (optional).
- Select Calculate for the accrued interest and total amount owed.
Related Calculations
Estimating what a judgment is worth in a settlement? See the Personal Injury Settlement Calculator, or check Probate Cost Calculator for estate-related costs.