About the Invoice Due Date Calculator
Payment terms are written in a shorthand that is easy to misread. This invoice due date calculator turns terms such as Net 30, 2/10 Net 30, Net 30 EOM and 15 MFI into exact calendar dates: the day the invoice is due, the last day to take any early-payment discount, and the weekday each falls on. If a due date lands on a weekend it also shows the next business day.
It is designed for accounts payable clerks scheduling payment runs, accounts receivable teams setting reminders, and small-business owners who want to know exactly when a supplier expects money. Enter the invoice amount to see the discount in dollars and the annualized cost of passing it up — a 2/10 Net 30 discount is worth more than 37% a year, which is why finance teams rarely skip it.
Net terms count calendar days from the invoice date. EOM (end of month) terms count from the last day of the invoice month, and MFI (month following invoice) terms fall on a set day of the next month. Some industries treat invoices dated on or after the 26th as if issued the following month — switch that on if your agreement says so. Public holidays are not considered; always check the wording of the actual contract.
How to use the invoice due date calculator
- 1Enter the invoice date.
- 2Choose the type of terms printed on the invoice.
- 3Fill in the net days, discount rate and discount period, or the MFI day.
- 4Enter the invoice amount to see the discount in money.
- 5Note the due date and discount deadline, and move weekend dates as your supplier allows.
Formula and method
Net terms add N calendar days to the invoice date, so an invoice dated October 15 on Net 30 is due November 14. A discount such as 2/10 Net 30 lets the buyer deduct 2% if paying within 10 days of the invoice date; otherwise the full amount is due on day 30. EOM terms start counting from the last day of the invoice month, and MFI (or “prox”) terms make the invoice due on a fixed day of the following month. With the 26th-day rule on, invoices dated on or after the 26th are treated as issued in the next month.
The annualized cost of skipping a discount treats the discount as interest for paying later: you give up d% of the invoice to keep (1 − d) of the money for the extra days between the discount deadline and the due date, scaled to 365 days. Weekend due dates are shown alongside the next Monday; public holidays are not adjusted.
- N
- Net days in the terms
- d
- Early-payment discount rate
- D
- Day of the following month for MFI terms
Worked examples
Net 30 from October 15
Thirty calendar days after October 15, 2026 is Saturday, November 14. Because that is a weekend, the next business day is Monday, November 16.
2/10 Net 30 on a $5,000 invoice
Paying within 10 days — by October 25 — knocks 2% ($100) off, so you pay $4,900. Waiting the extra 20 days to November 14 costs $100 on $4,900, which works out to about 37.2% a year.
2/10 EOM, Net 30 EOM
EOM terms count from October 31, the end of the invoice month. The 2% discount is available until November 10 and the full amount is due November 30, 46 days after the invoice date.
15 MFI with the 26th-day rule
An invoice dated October 27 falls after the 25th, so it is treated as a November invoice. Under 15 MFI it is due on the 15th of the following month: December 15, 2026.
Frequently asked questions
What does Net 30 mean?+
Net 30 means the full invoice amount is due 30 calendar days after the invoice date. Weekends and holidays are counted. Net 15, Net 45 and Net 60 work the same way with a different number of days.
What does 2/10 Net 30 mean?+
The buyer may take a 2% discount if paying within 10 days of the invoice date; otherwise the full amount is due within 30 days. On a $10,000 invoice that is $200 saved by paying 20 days early.
What does EOM mean on an invoice?+
EOM stands for end of month. Under Net 30 EOM the 30 days start from the last day of the month in which the invoice is dated, so an invoice dated October 5 or October 25 is due November 30 either way.
What do MFI and prox mean?+
MFI means month following invoice, and prox (proximo) means next month. Terms such as “15 MFI” or “15th prox” make the invoice due on the 15th day of the month after the invoice date.
Is it worth taking a 2/10 Net 30 discount?+
Usually yes. Skipping it is equivalent to borrowing at roughly 37% a year, far more than most credit lines cost. Unless cash is extremely tight, paying within the discount period is one of the best returns available to a business.
What if the due date falls on a weekend?+
Contracts differ. Many suppliers accept payment on the next business day, but some treat the calendar date as final. The safest approach is to send payment so it arrives by the last business day before the due date.