Late Invoice Interest Calculator
Enter the invoice amount, the yearly interest rate in your terms, the due date and the date you want to calculate to. You get the days overdue, the interest and the total payable.
Use the rate in your contract or terms.
Interest owed
₹1,479
30 days overdue
- Total payable
- ₹1,01,479
- Per day
- ₹49
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- Simple interest: amount × yearly rate ÷ 365 × days overdue. Late-payment interest is only chargeable if your contract or invoice terms provide for it.
How late payment interest is worked out
This uses simple daily interest: the amount, times the yearly rate divided by 365, times the number of days overdue.
Interest on late payment is only chargeable if your contract, purchase order or invoice terms say so, or if a law applies to your case. Check your terms before you add it to an invoice.
A clear due date and a stated late-payment rate on the invoice make it easier to ask for payment politely and on the record.
The formula
Interest = invoice amount × (yearly rate ÷ 100 ÷ 365) × days overdue.
Common questions
How do I calculate interest on an overdue invoice?
Multiply the amount by the yearly rate, divide by 365 and multiply by the number of days past the due date.
Can I charge late payment interest?
Only if your agreement or invoice terms provide for it, or a law that applies to you does. Check with your accountant or a lawyer if you are unsure.
Is the interest simple or compound?
Simple here: it is not added back and charged again. If your terms use compounding, the result will be higher.
What happens if the due date is in the future?
The days overdue show as zero and no interest is owed yet.
Send and track invoices in one place
SparkyInvoices handles GST-compliant invoicing for small businesses: draft, send and track invoices, so you can see what is overdue at a glance.
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