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PRODUCTIVITY

Invoice Due Date Calculator

Add payment terms to an invoice issue date and choose a reminder lead time to get due and reminder dates.

Tool statusRuns in your browser
Preview
prontouso://finance/invoice
CALENDAR DAYSAUTO UPDATE

Invoice terms

Set the payment terms and reminder.

INPUT
Payment terms
Reminder before due date
The grace period doesn't change the due date itself — it just adds one extra follow-up date.
Use business daysSkips Saturdays and Sundays in the term.
In this demo, business days mean Monday through Friday. Local holidays aren't taken into account.
● NO LOGIN · PROCESSED LOCALLY

Timeline

Key dates for this invoice.

RESULT
DUE DATEOVERDUE
Aug 29, 2026
DUE DATE
Issued on Jul 30, 2026
30 calendar-day term
10 days overdue
Today: Sep 08, 2026
Aug 24REMINDER
30TERM (DAYS)
10DAYS OVERDUE
Term overviewCALENDAR
01
02
03
Jul 30ISSUED
Aug 24REMINDER
Aug 29DUE DATE
The reminder's position is proportional to the total term.
Billing scheduleEVENTS
JUL 30
Invoice issuedStart of the payment term.
ISSUED
AUG 24
Send reminder5 days before the due date.
REMINDER
AUG 29
Invoice dueEnd of the 30-days term.
DUE DATE

How it works

  1. Enter your input

    Fill in the values, paste your text, or upload the file this tool works with.

  2. See results instantly

    Most tools update live as you type; a few use a single button. Either way, the result appears right on this page.

  3. Use your results

    Copy, download, or share what the tool produces — you're always in control of the output.

Privacy and processing — Runs locally in your browser. This tool does not upload your input.

What is Invoice Due Date Calculator?

An invoice due date calculator adds the payment term to an issue date to get the due date, suggests a reminder date before payment is due, and — when enabled — adds the term in business days instead of calendar days.

UNDERSTAND THE TOOL

How to calculate a due date, reminder, and grace period

Pick the issue date and the term — in calendar or business days — and the tool works out the due date, suggests a reminder date, and lays out the full billing schedule on a timeline.

Calendar days or business days

By default, the term counts every calendar day, which is how terms like net 15 or net 30 are conventionally written into contracts. Turning on 'Use business days' makes the tool skip Saturdays and Sundays while counting the term — Monday through Friday, without accounting for local holidays.

Due date (calendar days)
issueDate + termsDays
Due date (business days)
issueDate + termsDays, skipping Sat/Sun

Issued on Jul 30, 30 business-day term

Because the term skips weekends, the due date lands on Sep 10 — about 12 days later than the same 30 calendar days would give (Aug 29).

30 business days from a Thursday = Sep 10

The reminder and grace period are independent of the due date

The reminder date is always the due date minus the lead time you choose, counted in calendar days even when the main term uses business days — it's just a follow-up checkpoint before billing, and it doesn't affect the official due date.

The optional grace period adds calendar days after the due date and only creates one extra follow-up date on the schedule; it doesn't change when the invoice counts as overdue or generate a new due date.

How the status changes over time

  • Upcoming: more than a day remains before the due date.
  • Due tomorrow: it's due the following day.
  • Due today: the due date is today.
  • Overdue: the due date has already passed — the counter shows days overdue.

The reminder's position on the timeline

The reminder pin on the visual bar is positioned proportionally between the issue date and the due date — the closer to the due date, the further right it sits. This makes it easy to see at a glance whether the lead time you chose is short or generous relative to the full term.

Common payment terms

  • Net 15 / Net 30 / Net 45 / Net 60: payment due that many calendar days after the issue date — use the term shortcuts to fill these in quickly.
  • Due on receipt: a 0-day term — the due date matches the issue date.
  • A reminder 5–7 days before the due date is typically enough lead time without feeling premature.

A calendar estimate, not a billing system

The whole calculation runs in your browser — no date or amount is sent to a server. Business-day mode doesn't account for local holidays; confirm your contract's exact wording and the applicable holiday calendar before finalizing a billing schedule.

Frequently Asked Questions

Does business-day mode account for holidays?

No — it only skips Saturdays and Sundays. National, state, or local holidays aren't factored in; adjust manually if your contract accounts for them.

Can I use net 15, net 30, or another term length?

Yes — enter any number of days as a custom term, or use the 7, 15, 30, 45, and 60-day shortcuts as a starting point.

Does the reminder's lead time also switch to business days when I enable that option?

No — the reminder is always counted in calendar days from the due date, regardless of whether the main term is in calendar or business days.

What's the point of the grace period if it doesn't change the due date?

It creates an extra follow-up date on the schedule — useful for knowing when a second contact or a more formal collection step makes sense, without changing the official date the invoice counts as overdue.

What's the difference between the 'Due today' and 'Overdue' status?

'Due today' shows when the due date is the current date — still within terms. 'Overdue' shows starting the next day, once the day counter has passed the due date.

Why isn't the default issue date always today?

The starting example uses a fixed date to illustrate the calculation; use the 'Use today as issue date' button to fill in the current date quickly.

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