Late Payment Calculator
You enter the invoice, how many days it is overdue, and the annual interest rate you want to apply. The interest is simple: amount × rate × days ÷ 365. There is no built-in statutory rate for any country.
Calculator
How the number is produced
Interest = invoice × (annual rate ÷ 100) × (days ÷ 365). Total = invoice + interest.
Worked example
€1,000 overdue for 365 days at 10% a year is €100 of interest.
When this is useful
A contract names an interest rate and you want the arithmetic before you write to the client.
Limits
Not a statutory late-payment claim. No fixed compensation fees. The year is 365 days, not 360. This is not legal advice.
More on the assumptions is on how the calculators work.
Questions
Which official interest rate do you use?
None. If a law sets a rate where you invoice, look up that rate and type it.
Related tools
If a result disagrees with the formula on this page, email hello@gettowork.online.