Late Payment Interest Calculator
Calculates the interest added when money is paid late (damages for late payment). Enter the principal, the period and the interest rate to see the interest for each period and the total right away.
The day the debt was paid in full, or any day you want to calculate up to, such as today
The rate for an ordinary debt when no rate was agreed (Civil Act, Article 379).
Frequently asked questions
- What is the statutory interest rate for late payment?
- An ordinary debt with no agreed rate carries the civil statutory rate of 5% a year (Civil Act, Article 379), and a debt arising from trade or business carries the commercial statutory rate of 6% a year (Commercial Act, Article 54). If the contract sets a rate, you can also calculate with that agreed rate.
- Since when does the 12% Litigation Promotion Act rate apply?
- The rate under the Act on Special Cases Concerning Expedition of Legal Proceedings has been 12% a year since June 1, 2019; it was 15% from October 1, 2015 to May 31, 2019, and 20% from June 1, 2003 to September 30, 2015. A judgment usually orders it from the day after the copy of the complaint is served, and in cases where the hearings at first instance had already closed when the rate changed, the rate before the change continues to apply.
- How is late payment interest calculated?
- It is calculated as principal × annual rate × days ÷ 365, rounded to the nearest won. You can count the start date as a day too, as when a judgment orders payment “from [date] until the day of full payment”, and if the period spans a date on which the rate changed, it is calculated in separate parts.
- What if part of the debt has already been repaid?
- This calculator works out interest on one principal over one period, so if part was repaid or a judgment set a different period or rate, the actual amount will differ. In that case, list the dates and amounts repaid and talk to a lawyer.
This is a reference calculation based on statutory interest rates. If part of the debt has been paid, or if a judgment set a different period or rate, the actual amount will differ. Talk to a lawyer before deciding how much to claim or to pay.
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