What interest rate applies to a court judgment in my state?

It varies by state statute: California 10% (5% for certain medical/personal debt against individuals), New York 9% (2% for consumer debt), Massachusetts 12%, and Iowa uses the 1-year Treasury yield + 2%, which changes weekly. Each state page on this site cites the statute.

Is judgment interest simple or compound?

In these states it is applied as simple interest on the unpaid judgment (accruing daily, annual rate ÷ 365). Federal judgments differ: 28 U.S.C. §1961 compounds annually — use the federal calculator for those.

State judgment interest calculator

Simple daily interest on a money judgment at your state's statutory rate — each rate verified against the official statute text and cited on its own page.

Rate series Judgment amount ($)

Date interest begins (e.g. entry of judgment) Calculated through (e.g. payment date)

Estimate for reference only — courts, agencies and creditors may apply different rounding or conventions. Not legal, tax, or financial advice.

Assumptions: CA/NY/MA statutory rates have been stable for decades, so this calculator accepts start dates back to 1990 at the current rate. The NY consumer series applies 9% before April 30, 2022 and 2% from that date (the statutory transition). Iowa requires a judgment date within our weekly data (mid-2024 onward).

Know the carve-outs

California: 10% default — but 5% for judgments entered/renewed since 2023 against individuals on medical debt (<$200k) or personal debt (<$50k), and 7% against government entities. Rate applies to unpaid principal from entry of judgment.
New York: 9% general; select the 2% series for consumer-debt judgments against individuals (since Apr 30, 2022).
Massachusetts: 12% for tort and contract — an agreed contract rate displaces the contract default; the commonwealth pays a Treasury-linked rate capped at 10%.
Iowa: market-linked (1-yr Treasury + 2%), fixed per judgment from the H.15 value published just before it — pick the judgment date and this calculator applies that week's rate.

Federal-court judgments use a different statute and compounding — use the federal post-judgment calculator.