Late Payment Interest Calculator
Statutory interest on overdue invoices.
Enter your values
Enter the invoice amount in $.
Enter the annual interest rate in %.
Enter the days overdue you are working with.
Enter the fixed compensation fee in $.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Total now due
- $4,944.17
- Interest accrued
- $74.17
- Daily interest
- $1.58
- Compensation fee
- $70.00
Quick answer
Late payment interest accrues daily on the overdue amount from the day after the due date.
Interest = amount × rate × days ÷ 365
At a glance
| What it does | Statutory interest on overdue invoices. |
|---|---|
| Category | Business |
| Inputs needed | Invoice amount, Annual interest rate, Days overdue, Fixed compensation fee |
| Main output | Total now due |
| Formula | Interest = amount × rate × days ÷ 365 |
| Cost | Free — no sign-up, no download |
How to use the Late Payment Interest Calculator
- 1Enter the unpaid invoice amount.
- 2Enter the interest rate in your terms or statute.
- 3Enter days past the due date.
Inputs explained
- Invoice amount($)
- Enter the invoice amount in $.
- Annual interest rate(%)
- Enter the annual interest rate in %.
- Days overdue
- Enter the days overdue you are working with.
- Fixed compensation fee($)
- Enter the fixed compensation fee in $.
Worked example
Using the values the calculator loads with:
Inputs
- Invoice amount4800 $
- Annual interest rate12 %
- Days overdue47
- Fixed compensation fee70 $
Results
- Total now due$4,944.17
- Interest accrued$74.17
- Daily interest$1.58
- Compensation fee$70.00
Frequently asked questions
Can I charge interest without saying so?
In many jurisdictions statutory interest applies even without a contract clause.
Does interest compound?
Statutory late payment interest is usually simple, not compound.
What do I need to enter into the Late Payment Interest Calculator?
Just 4 values: invoice amount, annual interest rate, days overdue, fixed compensation fee. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Late Payment Interest Calculator work out the answer?
Late payment interest accrues daily on the overdue amount from the day after the due date. It applies the formula Interest = amount × rate × days ÷ 365 and shows the working so you can check each step by hand.
Is the Late Payment Interest Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.