Invoice & Payment Calculators
Calculate invoice due dates, real working-day due dates, late payment fees, and payment terms for any country. All calculations run in your browser.
Who these calculators are for
Invoice and payment calculators are used daily by finance teams, accounts receivable staff, freelancers, and business owners across every industry. They answer the most common invoicing questions without requiring accounting software:
- →Finance and AR teams tracking when customer invoices are actually due
- →Freelancers and agencies issuing invoices with Net 30 or Net 60 terms
- →Procurement and AP teams reconciling supplier payment dates against bank calendars
- →Operations managers checking whether a payment falls due on a non-working day
- →Legal and compliance teams calculating statutory late payment interest
- →Businesses invoicing international customers where local holiday calendars differ
Understanding payment terms
Payment terms define when an invoice must be paid. The most common formats are calendar-day terms: Net 7, Net 14, Net 30, Net 45, Net 60, and Net 90. These add the stated number of calendar days to the invoice date.
End-of-month terms work differently. EOM means payment is due at the end of the month in which the invoice was issued. EOM+30 means the end of the following month. 30 MFI (month following invoice) means the 30th of the month after the invoice date — a term common in French and Italian B2B invoicing.
The critical practical issue is that calendar due dates often fall on weekends or public holidays. In those cases, payment cannot be received until the next business day — which varies by country. The Real Due Date calculators on this page handle this adjustment automatically.
Invoice & payment calculators
Invoice Due Date Calculator
Enter an invoice date and payment terms (Net 30, Net 45, Net 60, EOM+30, etc.) to get the calendar due date. Covers all standard payment term formats used in UK, US, EU, and APAC invoicing.
Use when: Issuing invoices, chasing payments, or reconciling accounts receivable.
Real Due Date Calculator
Like the invoice due date calculator, but adjusts for weekends and public holidays so the due date falls on an actual working day. Returns the next business day when the calendar date falls on a non-working day.
Use when: B2B invoice management where payment must be received on a working day.
Invoice Late Fee Calculator
Calculate late payment interest on an overdue invoice using a statutory rate (e.g. Bank of England base rate + 8% under the UK Late Payment Act) or a custom contractual rate. Returns daily, weekly, and total accrued interest.
Use when: Chasing overdue invoices, issuing late payment demands, or reviewing debtor reports.
Net 30 Real Due Date Calculator
Dedicated Net 30 calculator that adds 30 calendar days to an invoice date and then adjusts to the next business day if needed. Country-specific holiday calendars for 40+ countries.
Use when: Quickly checking the real due date for Net 30 invoices in any country.
Invoice Real Due Date (country-specific)
Supports any payment term (Net 7 through Net 120) with country-specific business day adjustment. Choose from 40+ countries to account for local public holidays in your payment date calculation.
Use when: Cross-border invoicing where the paying country's public holiday calendar matters.
Net 30 from Today
Instantly shows what date is 30 calendar days from today — both the raw calendar date and the next working day adjusted date. No inputs required; updates automatically.
Use when: Quick reference for issuing a Net 30 invoice today.
Invoice Due Date from Payment Terms
Enter any invoice date and select from a full list of payment terms including EOM (end of month), MFI (month following invoice), and calendar-day terms. Covers terminology used across UK, US, Australian, and European invoicing practices.
Use when: Unfamiliar payment terms on a supplier invoice or customer PO.
Invoice payment workflow
A complete invoice-to-cash workflow typically uses these calculators together:
- Use the Invoice Due Date Calculator when issuing the invoice to confirm the expected payment date before sending.
- If the customer is in another country, switch to the Real Due Date Calculator to get the adjusted working-day date in their market.
- When an invoice passes its due date, use the Invoice Late Fee Calculator to calculate accrued statutory or contractual interest before issuing a payment reminder.
Responsible use
Late payment interest rates and statutory late payment rules vary by jurisdiction and may have changed since our calculators were last updated. The UK Late Payment of Commercial Debts (Interest) Act 1998, EU Late Payment Directive 2011/7/EU, and equivalent laws in other countries set specific statutory rates. Always verify the applicable rate with a legal or accounting professional before issuing a formal late payment demand.