Invoice Due Date Calculator
Calculate an invoice due date from the invoice date and payment terms. Choose a common term such as Net 30 or enter a custom number of days.
Calculate an invoice due date
Enter the invoice date, select the payment terms and choose how the days should be counted.
Results
Enter an invoice date and payment terms, then calculate the due date.
How to calculate an invoice due date
Start with the invoice date and add the number of days stated in the payment terms. For example, an invoice dated 1 September with Net 30 terms has a calculated due date 30 calendar days later.
For standard Net terms, the invoice date is day zero and the stated number of days is added to it.
What do Net 15, Net 30, Net 60 and Net 90 mean?
Net payment terms normally specify how many days a customer has to pay after the invoice date. Net 15 means 15 days, Net 30 means 30 days, and so on.
The calculator also supports Due on receipt, Net 7, Net 45 and a custom number of days so it can be used for less common payment periods.
Invoice Date vs. Receipt Date
This calculator measures the payment term from the invoice date. For example, Net 30 adds 30 days to the date entered as the invoice date.
Some contracts or payment arrangements may instead calculate the payment period from the date an invoice is received, approved or another specified event occurs. If your agreement uses a different starting date, enter that date in the calculator or calculate the due date according to the terms of the agreement.
Calendar days or business days?
Many invoice payment terms are expressed in calendar days. If a contract, purchase order or internal policy specifically uses business days, select the business-day option instead.
Business days in this calculator mean Monday to Friday only. Public holidays are not automatically excluded because holiday calendars differ by country and region.
What if the invoice due date falls on a weekend?
The calculator can leave the calculated date unchanged or move a Saturday or Sunday due date to the next Monday or previous Friday. The correct treatment depends on the agreement between the parties and any applicable rules.
Check the payment terms on your invoice or contract
This calculator treats standard Net terms as a number of days added to the invoice date. However, payment terms can be defined differently by a contract, purchase order, customer agreement or applicable law.
If your agreement specifies business days, a particular payment date, end-of-month terms or special treatment for weekends and public holidays, use those terms instead of the calculator's standard assumptions.
Payment deadlines and late-payment rules can also depend on applicable law. For an example, see GOV.UK guidance on when commercial payments become late .
Invoice due date example
An invoice is issued on 10 September with Net 30 payment terms.
Add 30 calendar days to the invoice date. The calculated invoice due date is 10 October, before applying any optional weekend adjustment.
Limitations
This calculator determines a date from the starting date and payment terms entered. It does not determine which payment terms apply to a particular invoice or whether a payment is legally overdue.
Business-day calculations exclude Saturdays and Sundays but do not automatically exclude public or bank holidays. The calculator also does not apply end-of-month terms, early-payment discounts, late-payment interest or other contract-specific conditions.
Check the invoice, contract, purchase order or other applicable agreement when an official payment deadline is required.
Invoice Due Date Calculator FAQ
How do I calculate an invoice due date?
Add the number of days in the payment terms to the invoice date. For example, Net 30 adds 30 days to the invoice date.
Does Net 30 mean 30 days from the invoice date?
That is the common interpretation used by this calculator. Always check the wording of the invoice, contract or purchase order if different terms have been agreed.
Are weekends included in Net 30?
When Net 30 is based on calendar days, weekends are included. If your agreement specifies business days instead, choose the business-day option.
Does this calculator exclude public holidays?
No. Business-day mode excludes Saturdays and Sundays only. Public holidays vary by jurisdiction and are not removed automatically.
Can I use custom payment terms?
Yes. Choose Custom number of days and enter the payment period you need.