28 U.s.c. 1961 Interest Rate Calculator

Calculate the statutory interest rate for federal judgments under 28 U.S.C. § 1961.

Interest Accrued Over Time

Interest Calculation Details

Description	Value	Unit
Judgment Amount	—	USD
Judgment Date	—	Date
Calculation End Date	—	Date
Average Weekly T-Bill Rate	—	%
Calculated Annual Interest Rate	—	%
Number of Days	—	Days
Total Interest Accrued	—	USD

What is the 28 U.S.C. 1961 Interest Rate?

The interest rate under 28 U.S.C. § 1961, often referred to as the federal judgment interest rate, is the statutory rate that applies to civil judgments entered in United States district courts. This rate is crucial for determining the amount of post-judgment interest that accrues on a monetary award. It ensures that a successful plaintiff is compensated for the time value of money between the date of the judgment and the date of payment. The rate is not fixed by judicial discretion but is tied to an objective benchmark: the weekly average yield on United States Treasury bills.

This calculator is designed for attorneys, litigants, financial analysts, and anyone involved in federal civil litigation who needs to accurately calculate the interest due on a federal judgment. Understanding this rate is essential for assessing the total amount owed and for dispute resolution concerning interest calculations.

A common misunderstanding revolves around when the rate is determined. It's important to note that the rate for post-judgment interest is fixed on the date the judgment is entered and remains constant for the duration of that specific judgment. It is not a floating rate that changes daily or weekly after the judgment date itself, though the *benchmark* rate used to determine the initial judgment rate is weekly.

28 U.S.C. § 1961 Formula and Explanation

The calculation of interest under 28 U.S.C. § 1961 is straightforward. The statute mandates that the interest rate shall be "the weekly average yield on United States Treasury bills, adjusted so as to equal, during that 1-year period, 13-week Treasury bill yields". For practical purposes, this translates to using the average auction rate for 1-year U.S. Treasury securities from the week the judgment was entered.

The primary formula used is:

Total Interest = Judgment Amount × (Annual Interest Rate / 365) × Number of Days

Variables Explained:

Variable Definitions and Units

Variable	Meaning	Unit	Typical Range / Source
Judgment Amount	The principal sum awarded in the federal court judgment.	USD	Any positive monetary value.
Judgment Date	The specific date the civil judgment was officially entered by the court. This date determines the applicable benchmark interest rate.	Date	Any valid date.
Calculation End Date	The date through which interest is being calculated. This is often the date of payment or a date specified by agreement or court order.	Date	Any valid date after the Judgment Date.
Average Weekly T-Bill Rate	The average interest rate for 1-year U.S. Treasury Bills, as published for the week ending on the Saturday closest to the Judgment Date. This is the benchmark rate.	Percentage (%)	Typically between 0% and 10%+, but can fluctuate significantly with economic conditions.
Annual Interest Rate Applied	The calculated annual interest rate derived from the Average Weekly T-Bill Rate, as per 28 U.S.C. § 1961. This is usually the T-Bill rate itself.	Percentage (%)	Same as Average Weekly T-Bill Rate.
Number of Days	The total count of days between the Judgment Date (exclusive) and the Calculation End Date (inclusive).	Days	Any positive integer.
Total Interest Accrued	The total amount of interest earned on the Judgment Amount over the specified period.	USD	Calculated value.

Practical Examples

Example 1: Standard Post-Judgment Interest

A plaintiff is awarded $50,000 in a federal lawsuit. The judgment is entered on January 15, 2023. The average yield on 1-year U.S. Treasury bills for the week ending January 14, 2023, was 4.50%. The defendant pays the judgment on March 31, 2023.

• Judgment Amount: $50,000
• Judgment Date: 2023-01-15
• Calculation End Date: 2023-03-31
• Average Weekly T-Bill Rate: 4.50%

The number of days from January 15, 2023, to March 31, 2023, is 76 days.

Annual Interest Rate Applied: 4.50%

Total Interest = $50,000 × (4.50 / 365) × 76 = $468.49

The total amount due would be $50,000 + $468.49 = $50,468.49.

Example 2: Higher Interest Rate Environment

In a different scenario, a judgment of $120,000 is entered on October 10, 2022. The average yield for 1-year T-bills that week was 3.75%. Payment is made on February 28, 2023.

• Judgment Amount: $120,000
• Judgment Date: 2022-10-10
• Calculation End Date: 2023-02-28
• Average Weekly T-Bill Rate: 3.75%

The number of days from October 10, 2022, to February 28, 2023, is 141 days.

Annual Interest Rate Applied: 3.75%

Total Interest = $120,000 × (3.75 / 365) × 141 = $1,736.99

The total amount due would be $120,000 + $1,736.99 = $121,736.99.

Notice how the *benchmark rate* (T-bill yield) applied to the *judgment date* is fixed. Even if T-bill rates increase significantly after October 10, 2022, the 3.75% rate still applies to this specific judgment.

How to Use This 28 U.S.C. § 1961 Calculator

1. Enter Judgment Amount: Input the exact principal amount of the federal judgment in U.S. Dollars.
2. Input Judgment Date: Select the date the judgment was officially entered by the court. This is critical as it determines the benchmark interest rate.
3. Set Calculation End Date: Choose the date up to which you want to calculate the accrued interest (e.g., the date of payment).
4. Find the Average Weekly T-Bill Rate: Locate the average yield for 1-year U.S. Treasury Bills for the week ending on the Saturday closest to your Judgment Date. This data can often be found through financial data providers or TreasuryDirect.gov archives. Enter this percentage value.
5. Click 'Calculate Interest': The calculator will process the inputs and display the total interest accrued, the specific interest rate applied, and the number of days in the calculation period.
6. Review Details: Check the detailed table below the results for a breakdown of all input values and the calculated annual rate.
7. Reset or Copy: Use the 'Reset' button to clear all fields and start over. Use 'Copy Results' to easily transfer the calculated figures.

Unit Considerations: This calculator works exclusively with U.S. Dollars and percentages. Ensure your T-bill rate is entered as a standard percentage (e.g., 4.5 for 4.50%). The dates must be in a standard YYYY-MM-DD format.

Key Factors That Affect 28 U.S.C. § 1961 Interest

1. Judgment Principal Amount: The larger the judgment, the higher the total interest accrued, assuming all other factors remain constant.
2. Judgment Date: This is arguably the most critical factor, as it anchors the applicable interest rate. A judgment entered during a period of high T-bill yields will accrue interest at a higher rate than one entered when yields are low.
3. Calculation Period (Number of Days): The longer the time between the judgment date and the payment date, the more interest will accrue. Even a low daily interest amount can add up significantly over extended periods.
4. Average Weekly T-Bill Rate: Directly influences the annual interest rate applied. Fluctuations in the broader economy and Federal Reserve monetary policy impact T-bill yields.
5. Week of Judgment Entry: Since the rate is tied to the *weekly* average yield, judgments entered just days apart but in different weeks could technically have slightly different benchmark rates if the weekly average changed significantly.
6. Definition of "Judgment Date": Clarity on when the judgment was officially "entered" is crucial. This is typically the date it is recorded on the court docket. Discrepancies here can lead to disputes over the correct benchmark rate.
7. Specific Court Rules or Agreements: While 28 U.S.C. § 1961 sets the federal standard, some specific contexts or contractual agreements might stipulate different pre-judgment interest or methods for calculating post-judgment interest, although post-judgment interest is generally governed by the statute.
8. Compounding: Standard 28 U.S.C. § 1961 interest does not compound. Interest is calculated on the original principal amount only. It is simple interest.

Frequently Asked Questions (FAQ)

Q1: Does the interest rate change after the judgment date?

A1: No. The interest rate is fixed based on the weekly average yield of 1-year U.S. Treasury Bills for the specific week the judgment was entered. It does not fluctuate with market rates after that point for that particular judgment.

Q2: What if I can't find the exact T-bill rate for that specific week?

A2: You should aim for the most accurate data available from reliable sources like TreasuryDirect.gov or reputable financial data archives. The "average yield" for the week ending Saturday closest to the judgment date is the standard.

Q3: Is the interest simple or compounded?

A3: Interest under 28 U.S.C. § 1961 is simple interest. It is calculated only on the original judgment amount, not on accrued interest.

Q4: Does this apply to state court judgments?

A4: No, 28 U.S.C. § 1961 specifically applies to civil judgments in United States district courts (federal courts). State courts have their own statutes governing interest on judgments.

Q5: What is the source for the T-bill rate data?

A5: Historically, the Federal Reserve Statistical Release H.15 was a common source. Current data can often be found on TreasuryDirect.gov or through financial data providers who track historical Treasury auction results.

Q6: How accurate does the "Calculation End Date" need to be?

A6: For precise calculations, especially when large sums are involved, using the exact date of payment or the date specified in a settlement agreement is recommended. For estimation, any reasonable date will suffice.

Q7: What happens if the judgment amount includes previously awarded interest?

A7: 28 U.S.C. § 1961 post-judgment interest applies to the principal amount awarded in the *current* judgment. If a prior judgment amount (including its own interest) is part of the new principal, then interest would accrue on that entire new principal sum. However, standard federal judgments typically accrue interest only on the specified monetary award.

Q8: Can this calculator be used for pre-judgment interest?

A8: No, this calculator is specifically for *post-judgment* interest as defined by 28 U.S.C. § 1961. Pre-judgment interest calculations can vary significantly based on the type of claim and jurisdiction and may require different formulas or rates.