Judgment Interest Calculator Guide for California

California judgment interest can change the value of a case fast. DocketMath helps you estimate post-judgment interest using the judgment amount, date, rate, and payment timing so you can see how much a money judgment may grow over time.

For timing context, California’s general limitations period for personal injury claims is 2 years under CCP §335.1. No claim-type-specific sub-rule is provided here, so treat that as the general/default period referenced for this guide.

What this calculator does

DocketMath’s interest calculator estimates how much interest accrues on a California money judgment between two dates. It is built for practical case tracking, settlement planning, and payoff estimates.

In California, post-judgment interest is governed by CCP §685.010, which sets the standard interest rate on a money judgment at 10% per year. That rate is simple interest, not compounding, unless a separate rule applies to a specific enforcement cost or statutory item.

Use the calculator to answer questions like:

• How much interest has accrued since entry of judgment?
• What is the current payoff amount?
• How much will a judgment grow by a future date?
• What happens if payment is delayed by 30, 60, or 180 days?

Typical inputs

What the output shows

The calculator typically returns:

• Accrued interest
• Total payoff
• Daily interest amount
• Amount due by a target date
• Effect of partial payments

A simple rule of thumb helps explain the math:

Interest = Principal × Rate × Time

For example, a $50,000 judgment at 10% annual simple interest generates about $5,000 per year in interest, or about $13.70 per day.

When to use it

Use DocketMath whenever you need a fast, defensible estimate of the growing balance on a California judgment.

Common use cases include:

• Settlement negotiation

  • Show the other side the current payoff figure.
  • Compare “pay today” versus “pay next month.”

• Collections planning

  • Estimate how long it will take for interest to accumulate to a target amount.
  • Track whether a proposed payment plan is reducing principal fast enough.

• Litigation budgeting

  • Estimate the financial impact of delaying enforcement steps.
  • Measure the cost of waiting for a hearing, motion, or appeal-related delay.

• Client reporting

  • Provide a clean, date-specific estimate of interest growth.
  • Explain how a judgment changes over time in plain numbers.

• Enforcement strategy

  • Evaluate the practical effect of waiting before pursuing writs, levies, or garnishment tools.

California judgment interest is not the same thing as pre-judgment interest, statutory costs, or attorney fee awards. If the judgment includes multiple components, calculate each one separately unless the order states otherwise.

Use it when the math needs a date

This tool is especially helpful when you need to calculate interest through a specific date such as:

• the date a payoff demand is sent
• the date of a scheduled enforcement hearing
• the date a debtor proposes to pay
• the date of a lien payoff inquiry

Quick checklist

For related workflow tools, see our /tools/interest calculator page.

Step-by-step example

Let’s walk through a straightforward California judgment interest example using simple interest.

Facts

• Judgment principal: $80,000
• Judgment date: January 1, 2025
• Interest rate: 10% per year
• End date: July 1, 2025
• No partial payments

Step 1: Calculate the time period

From January 1 to July 1 is 181 days in 2025.

Convert days to years:

• 181 ÷ 365 = 0.4959 years

Step 2: Apply the simple interest formula

• Interest = Principal × Rate × Time
• Interest = $80,000 × 0.10 × 0.4959
• Interest = $3,967.20

Step 3: Add interest to principal

• Total payoff = $80,000 + $3,967.20
• Total payoff = $83,967.20

Step 4: Look at daily growth

Daily interest at 10% on $80,000 is:

• $80,000 × 0.10 ÷ 365 = $21.92 per day

That means every day after the judgment date adds roughly $21.92 in interest, assuming no payments and a flat 10% annual simple rate.

Example summary table

What changes the result

The output will shift if any of these inputs change:

• a larger principal increases interest proportionally
• a later end date increases the interest period
• a partial payment lowers the balance and reduces future interest
• a different rate changes the daily and annual growth
• a different start date changes the whole calculation

Common scenarios

Different judgment situations need slightly different handling. The calculator is most useful when you know which category you are working in.

1) Straight money judgment

This is the cleanest case. If the court entered a money judgment and no special order changes the interest rules, the general California rule is 10% per year under CCP §685.010.

2) Judgment with a partial payment

If the debtor pays part of the balance, future interest usually runs on the remaining unpaid amount. That makes the payment date just as important as the payment amount.

Example:

• Original judgment: $100,000
• Payment: $25,000 on March 1
• Remaining principal: $75,000

After March 1, interest should be calculated on $75,000, not the full original judgment, unless the judgment or order says otherwise.

3) Long-delayed enforcement

Older judgments may accumulate large sums because interest keeps running until payment. A delay of even six months on a sizable judgment can add thousands of dollars.

Example:

• $250,000 judgment
• 10% annual interest
• 6-month delay

Estimated interest:

• $250,000 × 0.10 × 0.5 = $12,500

4) Case planning with the limitations period

For underlying claims, California’s general personal injury limitations period is 2 years under CCP §335.1. That is separate from judgment interest, but it matters at the front end of the case because filing timing affects whether a judgment is ever entered.

5) Post-judgment collections

When using a payoff figure in collection efforts, accuracy matters. Interest calculations often show up in:

• debtor examinations
• payoff letters
• lien releases
• settlement memoranda
• stipulations for payment plans

Tips for accuracy

Small date mistakes can create large payoff differences. These practices keep your calculation reliable.

Use the exact judgment date

California interest is tied to the judgment, so even a one-day error changes the amount.

• Check the filed judgment, not just the minute order
• Use the actual entry date shown by the clerk
• Confirm whether any amended judgment changes the starting point

Confirm the applicable rate

California’s general money-judgment interest rate is 10% per year under CCP §685.010. If a specific statute, federal rule, or special judgment type applies, the rate may differ.

Track partial payments separately

A payment on the wrong date can distort the whole payoff.

• Apply each payment on the date received or credited
• Recalculate from that date forward
• Keep a ledger of principal reductions

Separate principal from costs and fees

Judgment packages often include:

• principal
• accrued interest
• post-judgment costs
• attorney fees, if awarded
• enforcement expenses, if recoverable

These items may not all accrue interest the same way, so itemization helps prevent overstatement.

Use 365

Sources and references

Start with the primary authority for California and confirm the effective date before relying on any output. If the rule has been amended, update the inputs and rerun the calculation.

• Cal. Civ. Code § 3287

Related reading

• Interest rule lens: Maine — The rule in plain language and why it matters
• Common interest mistakes in Rhode Island — Common errors and how to avoid them
• Worked example: interest in Maine — Worked example with real statute citations