About This Calculator
JudgmentInterestRate.com is a free, publicly accessible tool for calculating statutory post-judgment interest for all 50 U.S. states and the District of Columbia. It is designed for attorneys, paralegals, pro se litigants, and anyone who needs to quantify the interest accruing on an unsatisfied court judgment. This tool is not affiliated with any court, government agency, or bar association.
Our Methodology
Post-judgment interest is calculated using simple (non-compounding) daily accrual. For each day in the accrual period, the calculator computes:
- Daily rate = Annual statutory rate ÷ 365
- Daily interest = Principal × Daily rate
- Segment total = Daily interest × Days in segment
For variable-rate states (like Florida), the accrual period is automatically segmented across every rate-change boundary. Each segment uses only the rate in effect for that period. Segment totals are summed to produce the total interest accrued.
For fixed-rate states, a single rate applies for the entire accrual period. The calculator applies the fixed rate from the judgment date through the selected end date.
Florida-Specific Methodology (§55.03, Fla. Stat.)
Florida post-judgment interest is governed by §55.03, Florida Statutes. The rate is set quarterly by the Florida Chief Financial Officer and published in the Florida Administrative Register. The rate equals the average Federal Reserve discount rate plus 400 basis points, rounded to the nearest quarter-percent.
This calculator maintains the complete historical quarterly rate table from 1981 through the current quarter, fetched directly from the Florida CFO's published rate schedule. The Worker API that powers the tool polls the CFO page monthly and updates the rate table automatically when new rates are published.
Rate Sources by State
Rates are sourced directly from official state government websites, state statutes, and court administrative publications. Below are the primary sources for the most frequently used states:
| State | Current Rate | Statute | Official Source |
|---|---|---|---|
| Florida | 8.25% (Q2 2026) | §55.03, Fla. Stat. | Florida CFO |
| California | 10% fixed | Code Civ. Proc. §685.010 | California Legislature |
| Texas | 5% fixed | Tex. Fin. Code §304.003 | Texas Legislature |
| New York | 9% fixed | CPLR §5004 | NY Senate |
| New Jersey | ~7.5% variable | N.J. Court Rule 4:42-11 | NJ Courts |
| Georgia | ~10.5% (prime+3%) | O.C.G.A. §7-4-12 | Georgia DOR |
| Illinois | 9% fixed | 735 ILCS 5/2-1303 | Illinois General Assembly |
| Massachusetts | 12% fixed | M.G.L. c. 235, §8 | MA Legislature |
| Nevada | Prime+2% variable | NRS 17.130 | Nevada Legislature |
| Virginia | 6% fixed | Va. Code §6.2-302 | Virginia Law |
Automatic Rate Updates
Florida quarterly rates are fetched automatically via a Cloudflare Worker that polls the Florida CFO's official rate page on the 1st of each month. When a new quarterly rate is published, it is parsed and stored in the Worker's KV database. The calculator uses the live API as its primary data source, with a full seed dataset as fallback.
For other states, rates are reviewed and updated manually in the codebase when statutory changes are enacted. Variable-rate states with annual resets (like New Jersey, Georgia, and Nevada) are checked annually.
Contractual Interest Calculator
In addition to statutory post-judgment interest, this tool includes a contractual interest calculator for computing interest on contract default claims. Users can input a principal amount, contractual interest rate, and date range to calculate interest accrued from the date of default. This is useful for demand letters and pre-judgment damages quantification in contract dispute cases.
How to Use the Results
The calculator produces a year-by-year (and where applicable, quarter-by-quarter and month-by-month) breakdown of accrued interest. Users can:
- Export to PDF for attachment as an exhibit to motions, demand letters, or court filings
- Export to Excel for further analysis — the workbook includes Summary, Annual, Quarterly, Full Detail, and Rate Reference worksheets
- Cite the applicable statute and rate source directly from the calculator output
The tool is designed to produce figures that match the methodology used in Florida and other state courts. However, always verify the output independently before use in any legal proceeding.
Contact & Feedback
This tool is maintained as a public resource for the legal community. If you identify a rate error, statutory change, or other inaccuracy, please report it via judgmentinterestrate.com. We aim to keep all rates current and the methodology accurate.