Calculate an Invoice Due Date From Payment Terms

Excel & Google Sheets

How it works

Dates in spreadsheets are just numbers counting days, so adding 30 to an invoice date lands exactly 30 calendar days later — month lengths and year rollovers are handled for you. For terms measured in months rather than days, use =EDATE(B2,1) to jump to the same day next month. If your terms are 30 business days, =WORKDAY(B2,30) skips weekends (and holidays if you list them in a range as a third argument). If the result shows a number like 46234 instead of a date, the cell just needs a date format.

B2

The invoice date. Must be a real date, not text.

+30

Adds 30 calendar days. Use 15, 45, or 60 to match your terms.

When to use it

Use this on invoice trackers, accounts receivable aging sheets, and payment reminder lists. Pair it with TODAY() to flag which invoices are past due right now.

Common mistakes

• ✕The invoice date is text, not a real date.

  ✓Adding 30 to text like "July 1" returns #VALUE!. Re-enter it as a date (right-aligned by default) or convert with DATEVALUE first.

• ✕Using =B2+"1 month" logic by adding 30 to everything.

  ✓Thirty days is not one month — Feb 1 + 30 lands in early March. For month-based terms, use =EDATE(B2,1), which handles short months correctly.

• ✕Counting weekends when terms are business days.

  ✓=B2+30 counts every calendar day. For 30 business days, use =WORKDAY(B2,30) — add a holiday range as the third argument to skip those too.

• ✕The result displays as a serial number.

  ✓A result like 46234 is correct — the cell is just formatted as a number. Change the cell format to Date.