About CalculateTax.uk

UK tax is not complicated because the rules are secret. HMRC publishes every rate, threshold, and allowance. The problem is that the information is scattered across dozens of GOV.UK pages, buried in policy papers, and written in language designed for accountants rather than ordinary taxpayers.

CalculateTax.uk was built to fix that gap. Instead of asking you to read through HMRC guidance and do the arithmetic yourself, we pre-compute the answer for thousands of specific scenarios and present it in plain language. If you earn £35,000 in England, there is a page that tells you your exact take-home pay, how much goes to income tax, how much to National Insurance, and what your effective rate is. No form to fill in, no account to create, no ads to close.

The project started in 2025 when the developer behind it could not find a single UK tax calculator that was free, transparent about its formulas, and covered more than basic salary calculations. Most existing tools either required personal data, showed intrusive advertising, or only handled a narrow slice of the tax system. We wanted something better: a comprehensive reference that anyone could use, verify, and trust.

CalculateTax.uk generates over 45,000 static calculation pages. Every page is computed at build time using the same underlying tax engine, which guarantees consistency across the entire site. The major sections include:

• Salary after tax for England, Scotland, Wales, and Northern Ireland, covering annual salaries from £10,000 to £150,000
• Hourly, weekly, daily, and monthly pay frequency conversions with full tax breakdowns
• Council tax for 769 local authorities, cross-referenced with salary levels and bands A through H
• Pension contributions at various percentages, showing the real cost after tax relief
• Bonus, overtime, and dividend tax layered on top of base salary
• Capital gains tax on property and shares, applying the correct rates for 2025-26
• Self-employed tax including Class 2 and Class 4 National Insurance at the current 6% rate
• Student loan repayments across Plans 1, 2, 4, 5, and Postgraduate, with 30-year repayment simulations
• Contractor scenarios including IR35, umbrella vs limited company, day rate equivalents, and CIS deductions
• Benefits and allowances such as marriage allowance, child benefit tax charge, salary sacrifice, company car BIK, maternity and paternity pay, statutory sick pay, and redundancy calculations
• Property taxes including stamp duty, inheritance tax, buy-to-let income tax, and rent-a-room relief
• NHS pay across all Agenda for Change bands and pay points
• Profession-specific salaries for over 100 UK occupations
• Regional comparisons between England, Scotland, Wales, and Northern Ireland for identical salaries

New sections are added regularly based on search demand and user requests.

Every figure on this site traces back to an official publication. We do not rely on third-party aggregators or user-submitted data. The primary sources are:

• HM Revenue & Customs (HMRC) for income tax rates and allowances, National Insurance thresholds and rates, PAYE guidance, dividend and savings allowances, capital gains tax rates, student loan thresholds, pension annual and lifetime allowances, CIS deduction rates, and self-assessment guidance.
• Scottish Government / Revenue Scotland for Scottish income tax rates and band thresholds, which differ from the rest of the UK under devolved powers.
• Valuation Office Agency (VOA) for council tax band data and local authority charge rates across England and Wales.
• Office for National Statistics (ONS) for median and average earnings data used in context sections and profession salary estimates.
• NHS Pay Review Body for Agenda for Change band rates and pay point values used in NHS salary calculations.
• Low Pay Commission for National Living Wage and National Minimum Wage rates by age group.

UK Government data is used under the Open Government Licence v3.0. Where we apply a formula or make an assumption beyond the raw rate, we document it on the methodology page.

CalculateTax.uk is a static site. All 45,000+ pages are pre-generated at build time, which means the HTML is computed once and served directly. There is no server-side processing when you visit a page, no database to query, and no API call to wait for. This architecture makes pages load quickly and eliminates the risk of runtime calculation errors.

The site runs on Astro, a static site generator optimised for content-heavy sites. The tax calculation engine is a single TypeScript module that every page imports. When we update a tax rate or fix a formula, every affected page is regenerated automatically in the next build.

Because the calculations are deterministic and the inputs are fixed (salary amounts, council names, pension percentages), we can verify every output against HMRC worked examples before publishing. This is fundamentally different from a dynamic calculator where bugs might only surface for certain input combinations.

We take accuracy seriously because tax figures affect real financial decisions. Every page is generated from the same calculation engine, so a rate error affects all pages in that category at once, making it both easier to detect and easier to fix.

When we discover an error, we fix it, log it publicly on our error log page, and document the corrected rate in our changelog. We believe transparency about mistakes builds more trust than pretending they never happen.

The calculation engine is updated each April when the new tax year begins. Mid-year rate changes (which are rare but do occur, for instance the NI cut that took effect in January 2024) are applied as soon as they are confirmed by HMRC. All pages currently reflect 2025-26 rates (6 April 2025 to 5 April 2026).

The site does not use cookies, does not store personal data, and does not log individual calculations. Static pages have no server-side processing at all. Interactive calculator pages (where they exist) run entirely in your browser. We do not use Google Analytics or any tracking pixel that shares data with third parties.

We do not sell data, run affiliate programmes, or accept sponsored placements. The site has no commercial relationship with HMRC, any accountancy firm, or any financial services provider.

The figures on this site are provided for information and estimation purposes only. They do not constitute professional tax, financial, or legal advice. Individual tax situations vary. Different tax codes, multiple income sources, benefits in kind, pension arrangements, and other factors can significantly affect the actual tax you owe.

For your personal tax position, consult HMRC directly at gov.uk/income-tax, use the official HMRC tax checker, or seek advice from a qualified accountant or tax adviser.

CalculateTax.uk is an independent service. It is not affiliated with, endorsed by, or operated by HMRC, the UK Government, or any public body.

Found an error in a calculation? Have a suggestion for a new calculator or section? You can reach us at [email protected]. We read every message and aim to respond within 48 hours on working days. If you are reporting a calculation error, please include the page URL and the figure you believe is incorrect, along with the source you are comparing against.