GovMath is an independent UK reference site. Our mission is simple: take the rules that govern your money — Income Tax, National Insurance, Stamp Duty, Universal Credit, student loans, pensions and dozens more — and translate them into calculators and explanations that make sense the first time you read them.
Government guidance is often technically correct but practically useless. It is written for civil servants and accountants, not for the person trying to work out whether a pay rise is worth it, how much Stamp Duty they owe, or what they can actually claim. We exist to close that gap.
What we do
Every GovMath tool follows the same promise. You get a fast, accurate calculator at the top of the page, and underneath it a plain-English explainer that covers three things:
- How we calculated your result — the maths, step by step, with no hidden assumptions.
- The official UK rules in simple English — what the law or HMRC/DWP guidance actually says.
- Common pitfalls — the traps and edge cases that catch people out, so you can avoid them.
Our principles
- Free, forever. No paywalls, no sign-ups, no email harvesting. We keep the lights on with unobtrusive advertising.
- Privacy-first. Calculations run in your browser. We do not store the figures you type in. See our Privacy Policy.
- Plain English. If a sentence needs a glossary, we rewrite the sentence.
- Kept current. Our figures track the latest published rates — currently the 2025/26 tax year.
How we keep figures accurate
Our rates and thresholds come from primary sources: GOV.UK, HM Revenue & Customs (HMRC), the Department for Work and Pensions (DWP), the Driver and Vehicle Licensing Agency (DVLA) and the devolved administrations in Scotland and Wales. When the government updates a rate, we update the calculator and note the tax year it applies to.
That said, GovMath provides estimates for general information. We are not a substitute for professional advice — read our Disclaimer for the full picture.
Who we are
GovMath is built and maintained by a small UK-based team of developers and writers who were tired of re-reading the same dense guidance pages every tax year. We are not affiliated with HMRC, the DWP, or any part of HM Government.
Get in touch
Spotted an error, or want a calculator we haven't built yet? We genuinely want to hear it — head to our contact page. Corrections are prioritised.