Penalty Interest Calculator
Calculate penalty interest on overdue debts per Thai Civil Code (5% p.a.) or contract rate
Penalty Interest Calculator
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Accrued penalty interest฿0.00
- Total amount owed
- ฿0.00
- Daily interest
- ฿0.00
- Monthly interest
- ฿0.00
- Rate applied
- 0.00%
- Remaining principal
- ฿0.00
Results are estimates only
Formula
Interest = principal × rate% × days ÷ 365 (simple) or principal × (1 + rate/12)^months − principal (compound)
Data as of
Results are estimates only
FAQ
Per Amendment 23 to the Civil and Commercial Code (effective 11 Apr 2021), the legal rate dropped from 7.5% to 5% p.a., and the default penalty rate from 9.5% to 7% p.a. (5% + 2%).
Penalty interest accrues daily: overdue principal × annual rate ÷ 365 × days overdue, counted from the default date until payment.
For non-financial-institution creditors, Section 654 caps interest at 15% per annum. Any excess is void. Banks and regulated lenders follow rates set by the Bank of Thailand.