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Late invoice fee calculator
Work out what a late fee adds to an overdue invoice: a flat fee, a monthly or yearly interest rate, or both.
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How to use it
- Enter the invoice amount and how many days late it is, or pick the due date and payment date.
- Enter the late-fee terms in your contract: a flat fee, an interest rate (per month or per year), or both.
- Choose pro-rated daily interest or a charge per started month, and any grace period.
- Copy the breakdown into a polite reminder. Check the limits where you and your client are first.
Everything runs in your browser. Nothing you type is sent or saved anywhere.
// want this in a spreadsheet?
See who owes you, before it's late.
The Freelancer Money Dashboard ($19) marks each invoice Paid, Not due yet, Due soon or Overdue, counts days overdue and shows what's unpaid on one dashboard. Google Sheets and Excel.
Not legal advice. Late fees and interest are limited by law in many places, and usually need to be agreed in writing before the work. Check your local rules or ask a qualified professional.
Questions
How is the late fee calculated?
Chargeable days = days late − grace period. Pro-rated: interest = invoice × annual rate × chargeable days ÷ 365 (a monthly rate is × 12 for the annual rate). Per started month: interest = invoice × monthly rate × the number of started 30-day months. Any flat fee is added once. It's simple interest, not compounded.
Can I charge any late fee I like?
No. Many states and countries cap late fees or interest, or only allow them if they were agreed in writing before the work started, for example in your contract or invoice terms. Check the law where you and your client are before you charge one. This calculator is not legal advice.
Should I use a flat fee or a percentage?
A flat fee is simple and easy to explain. A percentage scales with the invoice and keeps growing the longer it's unpaid. Some freelancers use both. Whatever you choose, put it in your terms up front.
What's 1.5% a month as a yearly rate?
1.5% a month is 18% a year as simple interest. On a $1,000 invoice that's about $0.49 a day, or $14.79 for 30 days.
Does the grace period remove the flat fee too?
Yes. In this calculator, if the invoice is paid within the grace period no fee applies at all.