Judgment interest calculator
A California money judgment earns 10% simple interest a year from the day it is entered. Nobody calculates it for you, so here is what you are actually owed.
The entry date on your SC-130, Notice of Entry of Judgment.
How judgment interest works in California
Once a money judgment is entered it accrues 10% simple interest a year on the unpaid balance. Simple, not compound — the interest does not itself earn interest. On a $5,000 judgment that is $500 a year, or roughly $1 a day.
This matters more than people expect, because judgments go unpaid for years. A California judgment is enforceable for 10 years and can be renewed before it lapses, so a debtor who stalls is not running down a clock in their favor — the debt is growing.
Collecting the interest
You have to ask for it and account for it. When you levy or garnish, your figure should include accrued interest, and MC-012, Memorandum of Costs After Judgment, is how you add both the interest and your enforcement costs — writ fees, sheriff fees, service fees — to what the debtor owes.
If partial payments have been made
Payments normally reduce the principal going forward, so interest after that date accrues on the smaller balance. This calculator applies payments to principal immediately, which is the simple approach; if there have been several payments over a long period, keep a dated ledger rather than relying on a single figure.
An estimate, not an accounting
This uses a 365-day year and treats payments as reducing principal from today. For a contested balance, or where payments were irregular, prepare a dated schedule showing each payment and the interest accrued between them.
Start with a demand letter
Most California small claims cases settle before anyone sees a courtroom. The letter is free to write, and you can have us print and certified-mail it for $29.
No account needed to start. We are not a law firm and cannot give legal advice.