Post Judgment Interest Calculator

What This Calculator Does

This calculator determines the interest that accrues on a court judgment from the date it was entered until the date it is paid. It uses the judgment amount, the applicable post-judgment interest rate, and the specific dates to compute the total interest owed. The result helps parties understand the full financial obligation beyond the original judgment principal.

How Post-Judgment Interest Is Calculated

The calculation follows a standard simple interest formula:

Interest = Principal × Annual Rate × (Days / 365)

The calculator counts the exact number of calendar days between the judgment date and the payment date. It then applies the annual interest rate proportionally for that period. This method assumes a 365-day year and does not compound interest.

Key Assumptions

• Interest accrues daily on a simple basis.
• The year is treated as 365 days.
• The interest rate remains constant over the entire period.
• No partial payments or credits are applied during the accrual period.

How to Use the Calculator

1. Enter the judgment amount — the principal dollar amount awarded by the court.
2. Enter the annual interest rate — the post-judgment rate set by statute or the court order (as a percentage).
3. Select the judgment date — the date the judgment was entered.
4. Select the payment date — the date the judgment is expected to be paid.

The calculator will display the total interest accrued and the total amount due (principal plus interest).

Example Calculation

A judgment of $50,000 is entered on January 1, 2023, with a post-judgment interest rate of 5% per year. The judgment is paid on January 1, 2025.

Days elapsed: 730 days (2 years)

Interest: $50,000 × 0.05 × (730 / 365) = $5,000

Total due: $50,000 + $5,000 = $55,000

This example assumes no partial payments and a constant rate throughout the period.

Understanding the Results

The output shows two figures:

• Total Interest Accrued — the amount of interest that has accumulated from the judgment date to the payment date.
• Total Amount Due — the original judgment principal plus the accrued interest.

These figures represent the full amount a judgment debtor must pay to satisfy the judgment in full. The calculation does not account for any payments already made, offsets, or adjustments ordered by the court.

Common Mistakes to Avoid

• Using the wrong interest rate. Post-judgment interest rates are often set by state or federal law and may differ from pre-judgment or contractual rates.
• Entering the rate as a decimal. Enter 5 for 5%, not 0.05.
• Incorrect date selection. The judgment date is the date the judgment was entered, not the date of the underlying incident or filing.
• Ignoring leap years. This calculator uses a 365-day year. For periods spanning February 29, the actual number of days may differ slightly from a strict 365-day assumption.

Limitations

• This calculator does not handle variable interest rates that change during the accrual period.
• It does not account for partial payments, credits, or setoffs.
• It assumes simple interest only. Some jurisdictions may require compounding under specific statutes or court orders.
• The result is an estimate. Always verify with a legal professional or the court for final amounts.

Practical Use Cases

• Judgment creditors can determine the total amount owed when preparing a demand for payment or writ of execution.
• Judgment debtors can calculate the amount needed to satisfy a judgment and avoid further accrual.
• Attorneys and paralegals can quickly compute interest for settlement negotiations, court filings, or client consultations.
• Individuals managing personal injury or contract judgments can understand the financial impact of delayed payment.