Late Fee Calculator
Chasing overdue invoices is easier with clear numbers. Enter the overdue amount, how many days late it is, and your fee terms — a flat percentage plus monthly interest — and the calculator shows the total late fee and the new amount due.
Result
Enter values to see the result.
How to use
- Fill in the fields above with your own figures — results update live as you type.
- Interest is charged pro rata: monthly percent divided across the exact days late. Add a flat fee percent if your terms include one.
- Check the result box and adjust any rate or parameter to test other cases.
Note: Late charges must match the terms agreed in your invoice or contract to be enforceable.
Tips
- State your late-fee terms on the original invoice — fees are far easier to collect when agreed upfront.
- Monthly interest compounds per month late, so long-overdue invoices grow quickly; follow up early.
- Check local rules before charging interest — some contracts and jurisdictions cap penalty rates.