Late fee calculator
Estimate a clear late payment fee.
Enter the invoice amount, days overdue, and late fee rate. Use the result for planning, then verify your contract terms and local rules before charging.
Invoice details
Late fee charged
$14.79
Original invoice
$1,000.00
Total now owed
$1,014.79
Calculation breakdown
Annual rate (equivalent)18.00%
Daily rate0.049315%
Days overdue30 days
Formula$1,000.00 × 0.049315% × 30
Pro tip: Add late fee terms to every invoice
Include "A late fee of 1.5% per monthly will be applied to overdue balances" in your invoice payment terms. Clear wording makes follow-up easier and helps clients understand the consequence of paying late.