Federal Post-Judgment Interest Calculator
Estimate post-judgment interest under 28 U.S.C. § 1961 using a federal annual rate, the judgment entry date, and the payment date. This calculator applies daily accrual with annual compounding and visualizes the balance growth over time.
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Enter your numbers and click Calculate Interest to see the accrued post-judgment interest, ending balance, and a growth chart.
Expert Guide to Calculating Federal Post-Judgment Interest
Federal post-judgment interest is the interest that accrues on a money judgment entered in federal court after the judgment is signed and docketed, but before it is paid. For lawyers, in-house legal teams, judgment creditors, judgment debtors, accountants, finance departments, and litigation support staff, getting this calculation right matters. It affects payoff letters, settlement discussions, accounting reserves, writs, and satisfaction-of-judgment calculations. Even a modest rate can produce meaningful dollars when a judgment remains unpaid for months or years.
The governing statute is 28 U.S.C. § 1961. In broad terms, the statute ties the interest rate to the weekly average 1-year constant maturity Treasury yield for the calendar week preceding the date of judgment. The statute also states that post-judgment interest is computed daily to the date of payment and compounded annually. That sounds simple, but in practice, people often make mistakes about the correct rate source, the correct start date, and whether the calculation should be simple interest or daily accrual with annual compounding.
What makes federal post-judgment interest different?
Federal post-judgment interest is not usually based on a contract rate, a state statutory rate, or a court-selected equitable number. Instead, it is usually governed by a federal statutory formula. The rate source is objective and publicly available, which improves consistency. The practical result is that the rate can be very low in some periods and comparatively high in others, depending on Treasury market conditions.
- The rate is tied to a published Treasury benchmark.
- The rate is generally determined by the week preceding the judgment.
- Interest accrues daily.
- Interest is compounded annually.
- The accrual continues until the judgment is paid.
Where the federal rate comes from
The statute points users to the weekly average 1-year constant maturity Treasury yield, as published by the Board of Governors of the Federal Reserve System. Practitioners commonly obtain the number from Federal Reserve statistical releases or Treasury-related historical rate resources. To avoid disputes, keep a copy of the published source used for the calculation in your file. If you are preparing a payoff demand, attaching the source rate can reduce back-and-forth with opposing counsel or a finance department.
Authoritative sources include the following:
- Federal Reserve H.15 Selected Interest Rates
- U.S. Courts judgment interest rate resources
- U.S. Treasury interest rate data
Step-by-step method for calculating federal post-judgment interest
- Identify the judgment amount. This is the principal balance on which post-judgment interest will accrue. Depending on the procedural posture, this may include taxable costs or amended amounts reflected in the entered judgment.
- Determine the judgment entry date. Use the actual date of entry of judgment. This date matters because it determines the applicable Treasury week and the accrual period.
- Find the correct federal rate. Look up the weekly average 1-year constant maturity Treasury yield for the calendar week preceding the judgment date.
- Compute daily accrual. Convert the annual rate to a daily rate by dividing by the applicable day-count basis.
- Apply annual compounding. Interest is computed daily, but if the judgment remains unpaid for more than a year, accumulated interest is added to principal annually.
- Continue through the payment date. The calculation ends on the date payment is made or another legally relevant cutoff date used for a payoff quote.
Formula overview
A practical estimate can be broken into annual segments:
- Daily interest for a segment: Current balance × annual rate × days in segment ÷ day-count basis
- Annual compounding: At each anniversary of the judgment, accrued interest is added to the balance
- Final payoff: Original judgment plus all accrued and compounded post-judgment interest
For partial years, many professionals use a straightforward daily accrual approach. For full years, they capitalize the accrued interest at the annual anniversary. This mirrors the statutory direction that interest is computed daily and compounded annually.
Selected published 1-year Treasury examples
The table below shows selected examples of published 1-year Treasury yields that illustrate how dramatically federal post-judgment rates can vary from one period to another. These are representative published market rates used here for comparison purposes and reflect the type of data practitioners review from Federal Reserve and U.S. Courts resources.
| Selected Week / Market Period | Example 1-Year Treasury Yield | Effect on Federal Post-Judgment Interest | Practical Meaning |
|---|---|---|---|
| Early 2021 | 0.10% | Very low post-judgment accrual | Large judgments accrued interest slowly when Treasury yields were near historic lows. |
| Early 2022 | 0.40% | Still modest accrual | Payoff growth was noticeable but often small relative to litigation spend. |
| Early 2023 | 4.73% | Substantial accrual increase | Delayed payment became far more expensive for judgment debtors. |
| Early 2024 | 5.02% | High accrual environment | Even short payment delays could create material additional liability. |
Illustration of dollar impact using real market-rate examples
To show how rate changes affect outcomes, the following table applies those example Treasury rates to a hypothetical $250,000 federal judgment over one year. The interest amounts below are rounded approximations and assume a one-year accrual period before compounding.
| Judgment Amount | Annual Federal Rate | Approximate 1-Year Interest | Approximate Year-End Balance |
|---|---|---|---|
| $250,000 | 0.10% | $250 | $250,250 |
| $250,000 | 0.40% | $1,000 | $251,000 |
| $250,000 | 4.73% | $11,825 | $261,825 |
| $250,000 | 5.02% | $12,550 | $262,550 |
Common mistakes people make
- Using the wrong benchmark. The rate is not simply any Treasury rate, prime rate, or state law rate.
- Using the wrong week. The statute refers to the calendar week preceding the date of judgment.
- Starting from the wrong date. Post-judgment interest runs from the date of entry of judgment, not from the verdict date or demand letter date.
- Forgetting annual compounding. Simple-interest calculations can understate the payoff on older judgments.
- Ignoring amended judgments or taxable costs. Changes in the judgment amount can change the interest base.
- Confusing pre-judgment with post-judgment interest. They are governed by different rules and often different legal sources.
How to use this calculator effectively
This calculator is designed for a practical estimate. Enter the judgment amount, the applicable federal annual rate, the judgment date, and the payment date. The calculator then computes daily interest and annual compounding over the selected period. The chart is especially useful for explaining the economics of delay to clients, insurers, finance teams, and settlement decision-makers.
If you are preparing a payoff statement, it is wise to preserve the following supporting materials:
- A copy of the entered judgment
- A screenshot or PDF of the source federal rate
- The exact calculation dates used
- Any assumptions about costs, offsets, or credits
- The spreadsheet or system output showing the arithmetic
Daily computation and annual compounding in plain English
Many users think annual compounding means interest is only added once per year and therefore should not be tracked daily. That is not the usual approach. Under the federal rule, you still compute the accrual day by day. If the judgment stays unpaid long enough to cross an anniversary, the accrued interest is then added into the balance, and the next period accrues interest on the higher amount. In other words, the balance can grow in steps at each annual anniversary, while the underlying accrual between anniversaries still happens daily.
For example, assume a $100,000 judgment and a 5.00% annual federal rate. Roughly speaking, the daily accrual is about $13.70 per day on a 365-day basis at the start. After one full year, the balance becomes about $105,000. In the second year, the daily accrual is no longer based on $100,000; it is based on the higher balance. That is the compounding effect.
Special issues to review before relying on any calculation
Even though the statutory framework is clear, some cases have special wrinkles. There may be amended judgments, remands, partial satisfactions, multiple defendants, separate awards, attorney fee orders, or post-trial motions that affect timing and amount. Bankruptcy, supersedeas bonds, sanctions awards, and appellate proceedings can also raise questions about when interest begins, what amount bears interest, and whether any portions of a judgment have already been satisfied.
For those reasons, this calculator should be used as a high-quality estimating tool rather than a substitute for legal advice in a contested case. If the dollars are significant, confirm the rate source, the judgment entry date, and any subsequent court orders before sending a final payoff demand.
Why this matters in negotiations and collections
Post-judgment interest can become a strategic factor almost immediately. In a high-rate environment, the cost of delay can be substantial, especially on six-figure or seven-figure judgments. Judgment creditors often use current payoff numbers to push collection efforts forward. Judgment debtors and insurers, on the other hand, need accurate and current payoff figures to evaluate whether continued delay is economically rational.
From a business standpoint, precision helps everyone. Creditors can avoid understating their demands. Debtors can avoid overpaying or disputing a miscalculated figure. Finance teams can reserve more accurately. And counsel can support negotiations with an objective, statute-based number rather than a rough estimate.
Bottom line
Calculating federal post-judgment interest requires four essentials: the correct judgment amount, the correct judgment date, the correct weekly federal rate, and the correct method of daily accrual with annual compounding. Once those pieces are in place, the math is manageable. The larger challenge is usually not arithmetic but legal accuracy: identifying the proper principal amount and the proper source rate for the right period.
If you keep your source documents, verify the governing statute, and use a consistent computational approach, you can produce a reliable estimate for most federal judgments. This calculator is built to make that process faster, clearer, and easier to explain.