Late Payment Fee Calculator

See how much interest and fees an overdue invoice has accrued.

Currency

Invoice amount

Days overdue

Annual interest rate (%)

Flat late fee (optional)

How it works

Interest = invoice amount × annual rate × days overdue ÷ 365 (simple interest). A flat fee is added once the invoice is late. Late fees must be stated in your contract or invoice terms, and legal limits differ by country and region.

Not legal advice. Check local rules before charging late fees.