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Late fee calculator

Late fee calculator for overdue invoices

Enter the invoice amount, how late it is, and the fee you agreed. The calculator shows the fee, the running total, and what the balance looks like if the client keeps not paying.

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Late fee type

The most common freelance term, e.g. 1.5% per month

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Your late fee appears here

Enter the invoice amount and how many days past the due date it is.

This is a calculator, not legal advice. Whether a late fee is enforceable, and at what rate, depends on your contract with the client and on the rules in your jurisdiction — which vary by state and by country, and differ again for consumer and business clients. Invoicito does not provide legal, tax, or accounting advice. Agree your late-payment terms in writing before the work starts, and take advice on the terms themselves if the amounts matter.

The three ways a late fee is calculated

Almost every late-payment term in freelance and small-business contracts is one of three shapes, and they produce very different numbers on the same overdue invoice.

  • Flat fee: one fixed amount once the invoice passes its due date
  • One-off percentage: a single charge of x% of the invoice balance
  • Monthly percentage: x% applied for each month, or part month, the invoice stays unpaid
  • Monthly rates are the ones that compound into real money — 1.5% a month is 18% a year

A late fee only works if it was agreed in advance

The calculator does the arithmetic. What makes the number collectable is that the client saw the term before the invoice was late — in the contract, on the quote, and printed on the invoice itself.

  • Put the late-payment term in the engagement contract, not only on the invoice
  • Repeat it on every invoice, in the payment terms block
  • Use an explicit due date rather than only 'Net 30' — clients read dates
  • Send a reminder before the due date; most late invoices are forgotten, not refused

Whether to actually charge it

The most common use of a late fee clause is as a deterrent that is never invoiced. That is a legitimate strategy, but it only works if the clause is visible from the start. Deciding to apply a fee that has never been mentioned turns a collections conversation into a dispute about the fee instead of about the original invoice — and the original invoice is the money you actually want.

  • Chase the balance first; add the fee once ordinary reminders have failed
  • Tell the client the fee is being applied before it appears on a statement
  • Waiving a fee is a concession worth trading for immediate payment
  • For a repeat client, weigh the fee against the relationship — once, not every time
  • If an invoice is far enough overdue to need a fee, it is also far enough overdue to stop new work

FAQ

Common questions

How do you calculate a late fee on an invoice?

Take the outstanding balance and apply whatever your agreed term says: a flat amount, a single percentage, or a monthly percentage multiplied by the number of months (or part months) the invoice has been overdue. This calculator does all three and shows the totals at 30, 60, and 90 days.

What late fee do freelancers commonly charge?

Terms of 1% to 2% per month are widely used in freelance and small-business contracts, alongside flat fees on smaller invoices. What you can actually charge depends on your contract and your jurisdiction, so treat these as common practice rather than as a limit.

Can I add a late fee that was not on the original invoice?

That depends on your contract and the rules where you operate, and it is worth getting advice on before you try. Practically, a fee the client never saw agreed is the hardest kind to collect — which is why the term belongs in the contract and on every invoice from the start.

Does the late fee compound?

Only if your terms say so. Most freelance terms apply a simple monthly percentage to the original balance rather than compounding on the accrued fee. This calculator uses the simple method, which is the more conservative of the two.