Late Payment Cost Calculator

Simple daily interest using 365 days. Whether fees are enforceable depends on your agreement and applicable law.

Your numbers

Enter your numbers to see the result.

How Late Payment Cost works

Potential late fee = unpaid amount × annual rate ÷ 100 × days overdue ÷ 365 + the flat charge entered. This mathematical estimate does not determine whether a charge is legally permitted.

A worked example

These sample values illustrate the calculation. Use your own numbers in the calculator for your result.

Example inputs
Invoice amount
1000
Days late
30
Annual interest assumption %
10
Fixed late fee
0
Potential fee
$8.22

Assumptions and limits

Simple daily interest using 365 days. Whether fees are enforceable depends on your agreement and applicable law.

Planning estimate only. This is not legal, tax, payroll or accounting advice.