Invoice Late-Fee Calculator
Calculate the interest and late fees owed on overdue invoices based on amount, days past due, and annual interest rate.
Automate invoicing and collections
LedgerPro tracks outstanding invoices, applies late fees automatically, and sends payment reminders — built for bookkeepers and CPA firms.
Try LedgerPro free →How this calculator works
Enter the original invoice amount, the number of days past the due date, and your annual interest rate. The calculator converts the annual rate to a daily rate, multiplies by the days overdue, and shows the accrued late fee plus the new total due.
Always disclose the late-fee policy on the invoice itself and in your engagement letter. Send a reminder 3-5 days before the due date to reduce delinquency.
Automate late-fee calculations so nothing slips through during busy season.
Frequently asked questions
What is a typical late-fee rate?
Most businesses charge 1-1.5% per month (12-18% annually). Check your state usury laws — some cap the maximum rate.
Should I charge late fees?
Yes, if your engagement letter or invoice terms include them. Late fees incentivize timely payment and compensate you for the cost of carrying receivables.
When do late fees start accruing?
Typically from the day after the invoice due date. Make sure your terms clearly state the grace period (if any) and the rate.