Smart Business Math

Invoice Due Date Calculator

Pick an invoice date and payment terms to see the due date and whether it’s coming up or already overdue.

Calculator

Results

Due date

Aug 22, 2026

From today

30 days

Net terms

Net 30

Copy Summary to paste the write-up. Copy Link for the same numbers every time. No login, no setup—just copy and go.

Invoice Due Date Summary

Due date = invoice date + net terms in days (e.g. Net 30). Knowing the date helps you forecast cash and follow up before receivables age out.

Explanation

Due date is the calendar day payment is expected.

From today shows days remaining or how many days overdue.

Business implication: long terms feel friendly but stretch cash—price and pipeline accordingly.

Step-by-step example

Invoice date July 1:

  • Net 15 → due July 16
  • Net 30 → due July 31
  • Net 45 → due August 15
  • Net 60 → due August 30

Formula

Due date = Invoice date + Net days

Helpful tips

FAQ

What is an invoice due date calculator?

An invoice due date calculator adds your payment terms (such as Net 15, Net 30, Net 45, or Net 60) to the invoice date so you know the calendar day payment is expected—and how many days remain or are overdue.

What does Net 15 mean?

Net 15 means payment is due 15 calendar days after the invoice date. It is a shorter term than Net 30 and usually improves cash collection speed.

What does Net 30 mean?

Net 30 means payment is due 30 days after the invoice date. It is one of the most common commercial payment terms for freelancers and small businesses.

What does Net 45 mean?

Net 45 means payment is due 45 calendar days after the invoice date. Longer terms can win deals but stretch receivables—plan cash and follow-ups accordingly.

What does Net 60 mean?

Net 60 means payment is due 60 calendar days after the invoice date. Use it when the contract requires it, and watch aging with accounts receivable days so cash does not lag delivery.

Do weekends change the due date?

This calculator counts calendar days. Some contracts shift weekend due dates to the next business day—check your agreement.

Should I invoice on the send date or service date?

Use whatever date your terms define as the invoice date. Many freelancers use the date the invoice is issued.

How accurate is this calculator?

It adds your term days to the invoice date in calendar days. Time zones and “as of today” use UTC date boundaries for consistency.

Related tools

Key terms

Invoice due date

Definition. The date payment is expected under your payment terms (Net 15, Net 30, due on receipt, etc.).

In simple terms. Clear due dates set collection expectations. They also feed cash-flow forecasts and late-fee policies.

Due date = invoice date + payment terms (in days)

Example. Invoice dated March 1 on Net 30 is due March 31.

Common mistake. Sending invoices without stated terms, then arguing about “late.”

Related calculators. Invoice Due Date Calculator, Late Fee Calculator

Related terms. Late fee, Accounts receivable days, Cash flow

Late fee

Definition. An extra charge applied when payment arrives after the due date, according to your terms and applicable rules.

In simple terms. Late fees can encourage on-time payment, but they must be disclosed and legally allowed. They are not a substitute for deposits and clear scope.

Late fee ≈ overdue amount × late fee rate (or a fixed fee, per your terms)

Example. A $2,000 invoice 15 days late at 1.5%/month (if allowed and disclosed) is modeled differently than a flat $25 fee.

Common mistake. Adding surprise fees that were never in the contract or invoice terms.

Related calculators. Late Fee Calculator, Invoice Due Date Calculator

Related terms. Invoice due date, Accounts receivable days

Accounts receivable days

Definition. How many days, on average, it takes to collect payment after a sale on credit.

In simple terms. Higher AR days mean more of your money sits in unpaid invoices. That affects runway and whether you need deposits or tighter terms.

AR days ≈ (accounts receivable ÷ revenue) × days in period

Example. If AR is $30,000 and monthly revenue is $45,000, AR days are roughly 20 on a 30-day basis (simplified).

Common mistake. Ignoring aging—averages can hide a few very late invoices.

Related calculators. Accounts Receivable Days Calculator, Invoice Due Date Calculator

Related terms. Cash flow, Invoice due date, Late fee

See all terms in the Glossary →

Notes & Assumptions

Net payment terms are standard commercial invoicing practice. Confirm wording in your contract or MSA.

Last reviewed: July 2026