Sumpath

About this site

Free, clear calculators for UK tax and pay, with the working shown and every figure traced back to GOV.UK.

Last reviewed 5 October 2026

Why this site exists

Working out what you will actually take home, or what a pay rise is really worth, should not need a spreadsheet and three GOV.UK pages open at once. Sumpath puts the rules in one place and does the arithmetic for you, then shows how it got the answer so you can check it.

Who runs it

Sumpath is designed, built and run by Abdul Basit, a solo developer. I made it because finding out what you will really take home, or what a pay rise is actually worth, should be quick and easy to check. Every calculator shows its working, and every figure is traced back to GOV.UK, so you never have to take a number on trust.

This is a small independent site run by one person. There is no team of advisers behind it, and nothing here is written by a regulated financial adviser or an accountant.

How we keep the figures right

  • Every rate and threshold is stored with a link to the GOV.UK or HMRC page it comes from and the date it was checked. The current figures were last checked against GOV.UK and legislation.gov.uk on 8 October 2026 (how we check).
  • The calculations are written as code and tested against worked examples before any page goes live.
  • Each tax year has its own set of figures. When the Budget changes the rules, we add the new figures and check them again before the new tax year starts.

The full method, including what our calculators leave out, is on the How we calculate page.

What this site is not

We are not HMRC and have no connection with the UK government. Our results are estimates to help you understand your money. They are not financial or tax advice. For decisions that matter, check with HMRC or a qualified adviser. See our disclaimer.

How the site is paid for

The calculators are free to use. We do not show adverts yet. In future we plan to show adverts from Google to cover running costs. If we do, they will be clearly labelled, kept apart from the calculators, and they will never affect the results. Our privacy policy will be updated before any adverts appear.

Spotted a mistake?

Please tell us. Our corrections policy explains what happens next, and you can reach us on the contact page.