Federal Court Judgment Interest Calculator

Estimate post-judgment interest under 28 U.S.C. § 1961 using the judgment amount, the judgment date, the payment date, and the applicable weekly average 1-year constant maturity Treasury yield. This calculator uses daily accrual with annual compounding, which reflects the statutory framework commonly applied to federal judgments.

Important: This tool is for educational and planning use. Federal post-judgment interest issues can involve amended judgments, partial payments, appellate modifications, costs, and case-specific rulings. Verify the controlling rate and methodology for your case.

Expert Guide to the Federal Court Judgment Interest Calculator

A federal court judgment interest calculator helps litigants, attorneys, insurers, finance teams, and judgment creditors estimate the amount of post-judgment interest that accrues after a money judgment is entered in federal court. In the United States, post-judgment interest in federal cases is generally governed by 28 U.S.C. § 1961. That statute ties the applicable rate to the weekly average 1-year constant maturity Treasury yield for the calendar week preceding the date of judgment. Although the concept sounds simple, practical calculation issues often create confusion. The right answer depends on the judgment date, the correct Treasury yield, the payment date, and the compounding approach required by statute.

This calculator is designed to make those steps easier. You enter the judgment principal, input the relevant Treasury yield, choose the judgment date, and choose the payment date. The tool then estimates the accrued interest using daily accrual with annual compounding. That mirrors the language in § 1961(b), which states that interest shall be computed daily to the date of payment and compounded annually. For lawyers and financial professionals who need a fast estimate before preparing a demand, evaluating settlement, or auditing a payoff statement, that framework is extremely useful.

What federal post-judgment interest is and why it matters

Post-judgment interest is designed to compensate the prevailing party for the time value of money between the date judgment is entered and the date the judgment is paid. Without post-judgment interest, a losing party could delay payment and effectively benefit from holding money that has already been adjudicated as owed. Congress addresses that concern by creating a statutory rate tied to a Treasury benchmark. Because Treasury yields move with market conditions, the federal post-judgment interest rate can be much lower or much higher depending on the period involved.

In a practical sense, post-judgment interest matters in several recurring scenarios:

• Settlement negotiations after entry of judgment
• Preparation of satisfaction figures for payment
• Insurance reserve analysis and exposure modeling
• Appeal strategy when payment may be delayed
• Collection actions and writ enforcement planning
• Accounting and accrual reporting for litigation liabilities

Even a relatively small interest rate can produce a meaningful figure when the principal is large or when payment is delayed for months or years. On a seven-figure judgment, a modest Treasury-based rate can still add thousands or tens of thousands of dollars over time.

The legal foundation: 28 U.S.C. § 1961

The central federal rule is 28 U.S.C. § 1961. In broad terms, it provides that interest shall be allowed on money judgments in civil cases recovered in a district court. The statute then sets the rate by reference to the weekly average 1-year constant maturity Treasury yield, as published by the Board of Governors of the Federal Reserve System, for the calendar week preceding the date of the judgment. The statute also states that interest is computed daily and compounded annually.

Key takeaway: In most federal money judgment situations, you do not choose an arbitrary rate, a state-law rate, or a contract rate unless a specific legal basis changes the analysis. The starting point is the federal statute and the Treasury yield benchmark tied to the week before judgment.

If you are looking for official source material, review the text of the statute and rate publications through authoritative sources such as the Cornell Legal Information Institute, the U.S. Department of the Treasury, and the Federal Reserve H.15 Selected Interest Rates release.

How this calculator works

The calculator follows a straightforward sequence:

1. Take the original judgment principal.
2. Apply the Treasury yield entered by the user as the annual post-judgment interest rate.
3. Count the number of days between the judgment date and the payment date.
4. Compute interest daily.
5. At each full anniversary year, capitalize the accrued interest into the balance.
6. Continue daily accrual on the new balance until the payment date.

This method reflects the language often summarized as “daily accrual, annual compounding.” It is more precise than simply multiplying principal by rate by total years because it respects the statutory compounding structure. If your case involves partial payments, supersedeas bonds, vacated judgments, amended judgments, separate cost awards, or other procedural changes, then a more tailored ledger may be necessary.

Why the Treasury yield matters so much

The applicable federal rate can differ dramatically from one year to the next. When one-year Treasury yields are low, post-judgment interest can be surprisingly modest. When rates rise, the same judgment can accrue significantly more interest over the same time period. That is why accurate rate identification matters so much. Using the wrong week or guessing at the rate can materially distort the payoff amount.

Selected Period	Approximate 1-Year Treasury Yield Environment	What It Means for Federal Post-Judgment Interest
Mid-2020	Roughly 0.1% to 0.2%	Interest accrual on federal judgments was very low compared with later years.
Mid-2022	Roughly 2.5% to 3.5%	Judgment interest became more noticeable, especially on larger commercial disputes.
Late-2023 to early-2024	Often around 4.8% to 5.3%	Federal judgment creditors could see materially larger post-judgment accruals than in the low-rate era.

These figures illustrate a real market pattern: one-year Treasury yields were near historic lows in 2020 and then rose sharply during the Federal Reserve tightening cycle. For a judgment creditor, timing can substantially change the economics of delay. For a judgment debtor, understanding the correct rate can influence whether early payment is financially preferable to extended negotiation or appeal.

Example calculation

Assume a federal judgment principal of $100,000, a judgment date of January 15, 2024, a payment date of January 15, 2025, and an applicable statutory rate of 5.25%. Under a simple one-year illustration, the estimated accrued interest would be about $5,250 if no other complications exist. If payment extends beyond one year, the balance after the first full year becomes the new base for subsequent daily accrual because the statute provides for annual compounding.

Now consider the same principal at a 0.15% rate, which was a realistic order of magnitude in parts of 2020. One year of interest on $100,000 would be only about $150. That difference shows why practitioners cannot rely on old habits or assumptions when estimating federal judgment interest. The current Treasury environment matters.

Principal	Rate	1-Year Estimated Interest	2-Year Estimated Growth With Annual Compounding
$100,000	0.15%	About $150	About $300.23 total interest after two years
$100,000	2.75%	About $2,750	About $5,575.63 total interest after two years
$100,000	5.25%	About $5,250	About $10,775.63 total interest after two years
$500,000	5.25%	About $26,250	About $53,878.13 total interest after two years

Common mistakes people make

One of the most common errors is using the rate that exists on the payment date instead of the rate tied to the calendar week preceding the judgment date. Another is confusing prejudgment interest with post-judgment interest. Prejudgment interest may arise under different legal sources, including federal common law, state law, or contract terms, depending on the case. Post-judgment interest under federal law generally follows § 1961 once judgment is entered.

Additional common mistakes include:

• Using a state statutory rate in a federal judgment context without confirming the governing law
• Failing to account for annual compounding
• Ignoring partial payments that reduce principal exposure
• Calculating from the wrong judgment date after amendment or remand
• Using a rounded rate without checking the official publication
• Overlooking whether costs or fees were included in the money judgment

Federal versus state judgment interest

Many users ask whether federal and state judgment interest rates are the same. The answer is usually no. State post-judgment interest statutes vary widely. Some states use fixed statutory rates, some use prime-based formulas, and some impose separate rules for contract actions or public entities. Federal court judgments in civil cases generally use the federal Treasury-based rule unless a specific legal reason directs otherwise. That distinction can be financially significant, especially in jurisdictions where state-law judgment rates are much higher than Treasury yields.

For that reason, users should always verify whether they are calculating a purely federal post-judgment interest obligation, a state-court judgment, or a federal judgment where another rule may affect the outcome. The title of the case and the court of entry matter. So does the wording of the judgment itself.

When a calculator estimate may not be enough

An online calculator is ideal for planning and estimation, but some circumstances justify a more detailed attorney or accountant review. Complex judgments can involve multiple awards entered on different dates, interest on taxable costs, fee awards entered later than the underlying merits judgment, sanctions, offsets, partial satisfactions, or appellate rulings that alter the original amount. In those situations, a single principal-and-rate input may not capture the whole picture.

You should consider a custom calculation when:

1. The judgment was modified after appeal.
2. There were one or more partial payments.
3. The case includes separately entered attorney fee awards or costs.
4. Different components of the award accrued from different dates.
5. The judgment language is ambiguous as to what was included.
6. An enforcement dispute has already arisen over the payoff amount.

How to find the correct Treasury rate

The safest method is to identify the judgment date, determine the calendar week immediately preceding that date, and then locate the weekly average 1-year constant maturity Treasury yield published through official sources. The Federal Reserve H.15 release and Treasury resources are the usual starting points. Once you confirm the rate, enter it into the calculator as a percentage. If the official source states 5.25, then enter 5.25, not 0.0525.

Because the rate is tied to a specific historical week, it does not change every day after judgment. The accrual amount grows over time, but the underlying annual rate used for the judgment typically remains the same unless a specific legal event changes the governing judgment.

Practical uses for lawyers, creditors, and finance teams

For law firms, this calculator can support post-trial case strategy, draft payoff statements, and help evaluate whether delay is economically sensible. For judgment creditors, it provides a way to monitor the increase in value while collection efforts continue. For defendants and insurers, it helps quantify the cost of carrying an unpaid judgment. For accounting and finance teams, it assists with reserve modeling and litigation exposure reporting.

The chart generated by the calculator is especially helpful because it visualizes how the balance grows from principal to accrued interest to total payoff. In long-running disputes, that visual can support management reporting and make settlement discussions more concrete.

Final thoughts

A reliable federal court judgment interest calculator is a practical tool, but it works best when paired with a correct legal understanding of § 1961. The key inputs are the judgment amount, the judgment date, the payment date, and the proper weekly average 1-year constant maturity Treasury yield from the preceding calendar week. From there, daily accrual with annual compounding provides a strong estimate of post-judgment interest.

If you need a fast, well-structured estimate, use the calculator above. If the case involves large exposure, multiple judgment dates, partial payments, or appellate complexity, use the calculator as a starting point and then validate the final figure against the record and the controlling authorities. In federal judgment enforcement, accuracy matters, and even small rate or date errors can produce meaningful differences in the final payoff amount.