Invoice Due Date Calculator
Calculate invoice payment due dates using standard net terms or custom days. Supports calendar and business day counting with overdue tracking.
Invoice Details
Formula
Due Date = Invoice Date + Payment Term (in calendar or business days)
Calendar days: add the term number directly to the invoice date regardless of weekends. Business days: advance one weekday at a time, skipping Saturday and Sunday.
Worked Example
Scenario: Invoice issued on Monday 3 March 2025. Payment terms: Net 30 calendar days.
Calculation: 3 March + 30 calendar days = Wednesday 2 April 2025.
If terms were Net 30 business days instead, the result would be approximately Wednesday 14 May 2025 — roughly 6 weeks later.
Always confirm whether your contract specifies calendar or business days.
Common Mistakes
- Assuming Net 30 means business days. Standard Net 30, Net 60 etc. almost always refer to calendar days unless the contract explicitly states otherwise.
- Starting the count from the day after. Day 0 is the invoice date. Day 1 is the next day. A Net 7 invoice dated Monday is due the following Monday.
- Ignoring the overdue indicator. If the due date is in the past, the tool flags it as overdue — check before chasing payment.
How to Use
- 1
Enter the invoice date
The date the invoice was issued to the client.
- 2
Select payment terms
Choose from Net 7 through Net 90, or enter a custom number of days.
- 3
Choose calendar or business days
Most standard net terms use calendar days. Switch to business days only if your contract specifies it.
- 4
Review the due date
The result shows the due date plus how many days remain — or flags overdue status.