Invoice due date calculator
Find the exact invoice due date.
Enter the invoice date and a payment term, and get the exact due date with a plain-language explanation — no guessing from a term like “Net 30.”
Quick answer
How is an invoice due date calculated?
Take the invoice date and add the number of days in the payment term.
- Invoice date:
- Sep 4
- Term:
- Net 30
- Due date:
- Oct 4
Plain calendar-day arithmetic, not business days — some contracts define due dates differently, so confirm what yours says.
Due date
Monday, October 5, 2026
An invoice issued on Saturday, September 5, 2026 with net 30 term is due on Monday, October 5, 2026. That's 30 days from today.
This is a plain calendar calculation (calendar days, not business days), not legal or tax advice — some contracts and jurisdictions define due dates differently, so confirm what your specific agreement says.
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Free to use on your own site — a bookkeeping blog, a freelancer resource page, anywhere it's useful. No account, no build step.
<iframe src="https://stitchinvoice.com/embed/due-date-calculator" width="100%" height="640" style="border:0;max-width:420px" title="StitchInvoice calculator"></iframe>Good to know
How due dates actually work.
The invoice date is the starting point, not the date work finished or the date it was opened
Most everyday payment terms count calendar days, not business days, unless a contract says otherwise
A due date that lands on a weekend doesn't automatically move — check what your agreement says
Write the due date on the invoice itself; don't make the client calculate it from the term
Recheck the date if the invoice date ever changes — the due date should always be recalculated, not adjusted by eye
Questions
Common questions about due dates.
How is an invoice due date calculated?
Take the invoice date and add the number of days in the payment term. Net 30 issued on March 1 is due March 31 — plain calendar-day counting, with no skipped weekends or holidays unless your specific agreement says to skip them.
Is Net 30 the same as 30 days?
Yes. "Net 30" is shorthand for "the full amount is due within 30 days of the invoice date." Net 15, Net 45 and Net 60 work the same way with a different number of days.
Does this account for weekends or holidays?
No — it's a straightforward calendar-day calculation. Some contracts move a due date landing on a weekend to the next business day; this tool doesn't assume that unless you account for it yourself.
Can StitchInvoice calculate this automatically?
Yes. Set a payment term once, and every invoice you create gets the correct due date automatically, with reminders that count down to it.
Never calculate a due date by hand again.
StitchInvoice sets the due date automatically from your chosen payment term, and counts down to it with reminders — no spreadsheet required.
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