FreeByte

Late payment interest calculator

Charge for overdue invoices.

Built and reviewed by Dovanic, Founder and editor, FreeByteLast reviewed: 2026-08-18
$
8%
$

You can charge

$210.47

Interest portion

$110.47

With these inputs, you can charge comes to $210.47. Interest portion works out to $110.47. The result assumes annual interest stays at 8%.

What moves the number · You can charge

Input−10%Now+10%
Invoice$199.42$210.47$221.51
Annual interest$199.42$210.47$221.51
Days late$199.42$210.47$221.51
Fixed fee$200.47$210.47$220.47

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Charge for overdue invoices.

A worked example

Starting figures

Invoice
$12,000
Annual interest
8%
Days late
42
Fixed fee
$100

What it returns

You can charge
$210.47
Interest portion
$110.47

How to read the results

With the defaults above, you can charge works out at $210.47.

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