About Calculate My Salary

Who runs the site

Calculate My Salary is operated by nisimetra, a small independent publisher focused on UK personal finance. The calculator, the underlying tax engine and every article on the site are written and reviewed by the Calculate My Salary Editorial Team — a small group of UK-based writers with professional experience in payroll, personal tax and financial software.

We are not regulated by the Financial Conduct Authority and we do not give personal financial, tax or legal advice. What we can do is show you, transparently, how HMRC's rules turn a gross salary into a net figure on a payslip.

Editorial policy

• Primary sources only. Every rate, threshold and formula on this site is taken directly from HMRC, GOV.UK, the Scottish Government, the Student Loans Company and The Pensions Regulator. We cite the exact publication we used whenever possible.
• No AI publishing without review. We use software to help draft and format content, but every article is fact-checked and edited by a human against primary sources before it goes live. Nothing is published unreviewed.
• No affiliate bias. We do not take money to recommend financial products, and we have no affiliate relationships with pension providers, ISA platforms or lenders. If that ever changes we will disclose it clearly in the relevant article.
• Transparent assumptions. Every calculation on the site has a plain-English assumptions page so you can see exactly what we modelled — and what we didn't.
• Clear dates and versioning. Each article shows when it was published and when it was last reviewed. When HMRC updates a threshold mid-year, we update the article and its “last updated” date.

How we build the calculator

The calculator implements HMRC's Payroll Technical Specification for Income Tax and follows the published order of operations for PAYE: gross pay, pension salary sacrifice, personal allowance, Income Tax, National Insurance and then student loan repayments. It covers rest-of-UK and Scottish tax bands, all five student loan plans, and both salary-sacrifice and relief-at-source pensions.

The tax engine has an automated test suite that runs on every change. If a band, rate or threshold changes between tax years, we update the engine, add a new year configuration and add a regression test so the numbers are locked in. You can see the detail on our How UK Salary is Calculated page, and the exact rates we currently use in the assumptions & methodology page.

Corrections policy

We take accuracy seriously. If you spot a rate, threshold or calculation that doesn't match HMRC, please contact us with the page and what you believe is wrong. We investigate every report, and where we find an error we publish a corrected version and note the change at the bottom of the article.

For urgent issues you can also email us at hello@calculatemysalary.co.uk.

Privacy and data

The calculator runs entirely in your browser — the salary you type is never sent to our servers, never saved to a database and never shared with third parties. We use minimal, consent-based analytics to understand which pages are useful. Full details are in our privacy policy.

Not financial advice

Calculate My Salary is an informational site. The results, guides and articles are for general information only and are not a substitute for personal financial, tax or legal advice. For decisions that depend on your individual circumstances, speak to a qualified professional or check HMRC guidance directly.