Post Judgment Interest Calculator

Simple interest, counted day by day

A judgment is not a payment. It is a court saying somebody owes you money, and between that day and the day the money actually arrives, interest runs.

This calculator works out how much has run. Give it the judgment amount, the rate, the date judgment was entered and the date you are counting to, and it returns the interest accrued.

It does it like this:

Daily interest = (Rate × Judgment amount) / 365

Accrued interest = Daily interest × Days elapsed

Three things to note about that, because each one is a convention rather than a law of nature.

The year is 365 days, flat, with no adjustment for leap years. Days are counted as whole days elapsed between the two dates, rounded down. And the interest is simple, which means it accrues only on the judgment amount and never on interest that has already accrued.

That last one is the important one, and it is the difference between this calculator being right for your case and being wrong for it.

Whether it compounds depends on which court

There is no single rule for post-judgment interest. There is a federal rule, and then there are as many state rules as there are states, and they do not agree with each other on either the rate or the method.

Federal judgments compound

Post-judgment interest on a money judgment in a US district court is governed by 28 U.S.C. § 1961. The statute is short and it is specific: interest runs from the date of entry of the judgment, is computed daily to the date of payment, and shall be compounded annually.

Compounded annually. So on a federal judgment, at the end of each year the accrued interest is added to the principal and the following year's interest runs on the larger figure.

This calculator does not do that. It computes simple interest. For a federal judgment outstanding less than a year the two are identical, and beyond a year this calculator will give you a figure below what the statute produces.

Many state judgments do not

State rules are the opposite of uniform. Many states apply simple interest at a fixed statutory rate, and for those this calculator's method is the correct one. Others compound, some annually and some otherwise. Rates range from a couple of percent to double digits, some are fixed by statute and some float against a published benchmark, and some vary by the type of case.

So the sequence is: find out which court entered the judgment, find the rule that court applies, and only then decide whether the number on this page is the number you want.

Some other federal carve-outs worth knowing about. Section 1961 does not apply to internal revenue tax cases, where the underpayment or overpayment rates under section 6621 of the Internal Revenue Code apply instead. Criminal judgments and condemnation proceedings run under their own statutes.

What the difference actually comes to

Worth putting numbers on, because compounding sounds like a technicality until you see it over a few years.

A judgment of 50,000 at 4.5 percent:

Identical in year one, then the gap opens and keeps opening. At ten years the simple figure is short by more than five thousand, which is over a fifth of the interest owed.

So if you are working with a federal judgment more than a year old, take the figure from this calculator as a floor rather than an answer. Judgments that sit unsatisfied for years are exactly the ones where the method matters most, and they are also, unfortunately, common.

Finding the rate, which is not a number you choose

The calculator asks you for a rate, which might suggest you get to pick one. You do not. It is set by whichever rule governs your judgment, and it is a fact to be looked up rather than an assumption to be made.

For a federal judgment the statute pegs it to the weekly average one year constant maturity Treasury yield, as published by the Board of Governors of the Federal Reserve System, for the calendar week preceding the date the judgment was entered.

Every part of that sentence does work.

The week preceding. Not the week of the judgment. If your judgment date happens to be the same day the Federal Reserve publishes, the prior week's rate is the one to use, because the release counts as issued at close of business.

Fixed at entry. The rate is variable in the sense that different judgments get different rates, but for your judgment it is locked in on the day it was entered and does not move afterwards. A judgment entered when the one year yield was near zero keeps that rate for its whole life, however much rates rise later.

The published rates come from the Federal Reserve's H.15 Selected Interest Rates release, under Treasury constant maturities, one year. Federal courts publish historical tables of the applicable weekly rates, which is usually the easier route: find the week ending immediately before your judgment date and read the rate off.

For a state judgment, the rate is whatever that state's statute says. Some are a flat number that has not changed in decades. Others float. Your judgment paperwork or the clerk's office is the place to confirm it.

A fifty thousand dollar judgment

Judgment of 50,000, rate of 4.5 percent, entered and then outstanding for 943 days.

The daily rate. 4.5 percent of 50,000 is 2,250 a year. Divided by 365 that is 6.1644 a day.

The elapsed time. 943 days, which the calculator reports as 134 weeks and 5 days.

The interest. 6.1644 times 943 is 5,813.01.

So a little over two and a half years of delay has added 5,813.01 to what is owed, and the full amount due is 55,813.01.

The calculator shows you the interest but not that final total, so add the judgment back yourself. It is the number that goes on the demand.

And if this were a federal judgment, that 5,813.01 would be understated. At 943 days you are past the first annual compounding point, so the statutory figure would be somewhat higher.

Which dates to put in the boxes

Date of Judgment. The date judgment was entered, which is what the federal statute keys off. That is not necessarily the day of the hearing, the day the decision was announced, or the date on the opinion. Entry is a docketing event and the docket is where to confirm it. A few days of difference is small money, but it is the kind of small money that gets argued about.

Date of Writ. Whatever date you are counting up to. The field is named for the point at which a writ of execution issues, since that is a common moment to need the figure, but nothing in the arithmetic requires it. Use the date of payment, the date of a demand letter, or today. Interest runs to payment, so the end date is simply wherever you are standing.

Both must be real dates and the second must be after the first, or the calculator will refuse. Time is counted as whole days elapsed and rounded down, so a partial day at either end is dropped rather than counted.

One practical note if the debt is being paid in instalments rather than all at once. This tool assumes the judgment amount sits unchanged for the whole period. Partial payments reduce the balance, and from that point interest should run on the smaller figure. For that you would need to calculate each period separately and add the pieces, or work from a proper ledger.

Questions people ask

Does this calculator compound?

No, it computes simple interest on the judgment amount. That matches many state statutes. It does not match the federal rule, which requires daily computation compounded annually, so for a federal judgment over a year old this figure will be low.

What rate applies to a federal judgment?

The weekly average one year constant maturity Treasury yield for the calendar week before the judgment was entered, published by the Federal Reserve. Federal courts publish historical tables so you can look up the right week.

The Treasury yield has changed since my judgment. Does my rate change?

No. The rate is fixed at entry and stays with that judgment for its whole life, whatever happens to yields afterwards.

When does interest start running?

From the date the judgment is entered, under the federal statute. Pre-judgment interest, covering the period before that, is a separate question governed by different rules.

Why does the result not include the judgment amount?

It reports the accrued interest only. Add your judgment amount to it for the full sum due.

What if partial payments have been made?

Then the balance changed and so did the daily interest. Calculate each period separately against the balance that applied during it, and add them together.

Does it handle leap years?

The day count is exact, so a leap day between your two dates is counted. The divisor is a flat 365 rather than 366, which is the convention many statutes use, though not all of them.

References

A note on the sources, which matter more than usual here. The federal rule is a statute rather than a practice, and the text below says in terms that interest is computed daily and compounded annually, which is the single most important thing on this page. The rate is not discretionary either: it is tied to a specific Federal Reserve publication for a specific week, and the federal courts publish the applicable historical rates. State rules differ from all of this and from each other. None of this is legal advice, and for anything being filed or enforced the governing statute and your own counsel are what to rely on rather than a calculator.

1. Office of the Law Revision Counsel, United States House of Representatives, 28 U.S.C. § 1961, Interest, providing that post-judgment interest runs from the date of entry at the weekly average one year constant maturity Treasury yield for the calendar week preceding the judgment, is computed daily to the date of payment, and shall be compounded annually. https://uscode.house.gov/view.xhtml?req=%28title%3A28+section%3A1961+edition%3Aprelim%29
2. Administrative Office of the United States Courts, Post-Judgment Interest Rate, on the statutes governing civil, criminal and condemnation judgments and the Treasury yield used to set the rate. https://www.uscourts.gov/court-programs/fees/post-judgment-interest-rate
3. Board of Governors of the Federal Reserve System, H.15 Selected Interest Rates, the published series from which the one year Treasury constant maturity yield is taken. https://www.federalreserve.gov/releases/h15/
4. Cornell Law School, Legal Information Institute, Compound interest, Wex legal dictionary, on interest computed on principal and on accumulated interest. https://www.law.cornell.edu/wex/compound_interest