Late Fee Calculator
100% PrivateBusiness & Finance UtilitiesWork out the fee on an overdue invoice for flat, percentage or interest terms.
Runs entirely in your browser. Your input is not uploaded to Ovatly or anywhere else.
Pick the due date to see the fee for the terms you entered.
This calculator only does the maths of the terms you enter. It is not legal advice and does not say what fee you may charge: late fee rules differ by contract and by country.
- 1Enter the overdue amount, the due date, and the date to calculate up to.
- 2Choose the fee type from your agreement: flat fee, percent per period simple, or percent per period compounding.
- 3Enter the fee or the rate and period, then read the days overdue, the fee and the total now due.
Due 25 September 2026 and calculated on 9 November 2026, the payment is 45 days overdue, which is 1.5 monthly periods. The simple fee is 2,000 x 1.5 percent x 1.5 = 45.00, so the total due is 2,045.00. On compounding terms the same inputs give a fee of about 45.17.
- Percent periods are treated fractionally: 45 days at a 30-day period is 1.5 periods, for both simple and compound modes. If your agreement counts only whole periods, adjust the dates so the period count comes out whole.
- Money figures are rounded half-up to 2 decimal places for display.
- Late payment law, interest caps and notice requirements differ by country and by whether the customer is a business or a consumer. This calculator checks none of that.
Simple charges the rate on the original amount only. Compound charges it on the amount plus fees already accrued, so the fee grows faster the longer the payment is late.
About this tool
The Late Fee Calculator works out the fee on an overdue amount for the terms you enter: a flat fee, or a percent per period charged simply or with compounding. It exists to do the arithmetic of an agreement you already have. It is not legal advice and it does not tell you what fee you are allowed to charge.
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Part of Ovatly's free tools in Business & Finance Utilities.