Invoice Due Date Calculator
Enter the invoice date and the number of calendar days in your payment term. The calculator returns the exact due date you can place on the invoice.
Formula: Due date = invoice date + payment-term calendar days.
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Enter the numbers
Use 0 for due on receipt.
Calculated result
Invoice due date
Friday, October 16, 2026
30 calendar days after the invoice date
Suggested reminder date
Tuesday, October 13, 2026
Three calendar days before payment is due
Formula: Due date = invoice date + payment-term calendar days.
Use the result correctly
What the calculation means
Write the actual date on the invoice even when you also state Net 30 or another term. A specific date is easier for the customer and accounts-payable system to act on. This calculator uses calendar days, not business days.
Useful for
- Translate Net 15, Net 30, Net 45, or Net 60 into an exact date
- Set a reminder before the customer payment is due
- Check a custom payment term before sending the invoice
Worked examples
Due date calculation examples
Use these examples to check the formula, then replace the figures with the real values for your transaction.
| Scenario | Input | Calculated result |
|---|---|---|
| Scenario Net 15 | Input Invoice dated August 1, 2026 | Calculated result Due August 16, 2026 |
| Scenario Net 30 | Input Invoice dated August 1, 2026 | Calculated result Due August 31, 2026 |
| Scenario Due on receipt | Input Invoice dated August 1, 2026 with 0 days | Calculated result Due August 1, 2026 |
Frequently asked questions
Does Net 30 use calendar days or business days?
Net 30 normally means 30 calendar days unless the agreement explicitly says business days. Put the exact due date on the invoice to remove ambiguity.
What date should I use for due on receipt?
Use a payment term of 0 days. The due date is the same as the invoice date, although the customer payment method may still take time to process.
Does the invoice date count as day one?
This calculator adds the full term after the invoice date. For example, an invoice dated August 1 with Net 30 is due August 31.
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