Business Days Calculator
Count working days between two dates, skipping weekends and — if you tick the box — the published 2026 US federal or UK bank holidays.
Deadline Calculator
Add or subtract business days from any date to find a filing, response, or processing deadline — the way offices actually count them.
Check Digit Validators
Test the built-in maths of card-style numbers (Luhn), ISBN-10, ISBN-13 / EAN-13 and UPC-A codes. Typing check only — never a lookup.
VAT Number Format Checker
Check whether a VAT or EIN number is the right shape for its country — GB, the main EU formats, and the US EIN pattern.
Retirement Date Estimator
Pick a retirement age from 60 to 70 and see the exact date, how long is left, and the month payments would normally start.
Pay Grade Salary Calculator
Convert an annual salary to monthly, biweekly, weekly and hourly — and project five years of increments.
Leave Planner Calculator
Work out pro-rata annual leave for part-time staff and mid-year starters with the standard entitlement formula.
What this site is — and what it is not
GovOfficeKit is a set of general office calculators. It helps you count, convert, and sanity-check figures using standard, published methods: weekend and holiday arithmetic, the public check-digit algorithms built into card and book numbers, country VAT format patterns, and ordinary pay and leave maths.
It is deliberately not a government service. It holds no records, searches no database, and cannot verify that any person, business, document, or number is genuine. Where a tool touches a number format, it checks only that the number is shaped and summed correctly — the same check any spreadsheet can do. Confirm anything official with the issuing authority.
Private by design
Every calculation runs in your own browser the moment you type. Nothing is uploaded, logged, or stored — close the tab and the figures are gone. That makes these tools safe for the rough workings, drafts, and “what-if” figures that pass across an office desk every day.