About WebCalculator

Who runs WebCalculator

WebCalculator is an independent website operated by Mustafa Bilgic. It is not connected to HM Revenue & Customs, GOV.UK, any bank, lender, accountancy firm or government department. We are a small, privately run publisher that builds free online calculators for people across the UK who want a fast, honest answer to an everyday money question — without filling in a form, creating an account or handing over personal details.

The idea behind the site is simple. The official rules for Income Tax, National Insurance, student loans, pensions, Stamp Duty and mortgages are all published — but they are spread across dozens of GOV.UK pages, written in dense language, and change every tax year. Most people just want to know one thing: "what does this actually mean for me?" WebCalculator exists to answer exactly that, in seconds.

What WebCalculator does

The site brings together more than a hundred purpose-built UK calculators in one place. These cover the money decisions that matter most:

• Pay & tax — take-home pay, Income Tax, National Insurance, salary sacrifice, bonus tax and self-employed tax for the 2026/27 tax year.
• Property & mortgages — mortgage repayments, affordability, Stamp Duty (including first-time buyer relief), buy-to-let yield and remortgaging.
• Savings & loans — compound interest, ISAs, premium bonds, personal loans and car finance.
• Pensions & retirement — pension pots, annuities, drawdown, the State Pension and tax-free lump sums.
• Profession pay — specialist take-home calculators for NHS staff, teachers, junior doctors, the police, firefighters and the armed forces, with the right pay scales and pension schemes built in.

Every tool runs entirely in your browser. You don't sign in, and the numbers you type are never sent to us or stored on a server — the calculation happens on your own device.

Our commitment to accuracy

Money calculators are only useful if the figures behind them are right. That is why every WebCalculator tool is built against primary UK sources rather than copied from other websites:

• Tax bands, allowances and thresholds come from HMRC and GOV.UK — for example the £12,570 Personal Allowance, the 20% / 40% / 45% Income Tax bands, and the 8% and 2% Class 1 National Insurance rates for 2026/27.
• Student loan thresholds and repayment rates follow the official plan rules (Plan 1, 2, 4, 5 and Postgraduate).
• Mortgage, pension and savings tools use standard, transparent financial formulas — the same maths a lender or actuary would use.

We re-check the figures at every Budget and Spring Statement, and update the calculators when HMRC changes the rates. Where a result depends on assumptions — such as an illustrative annuity rate or a standard tax code — we say so clearly on the page so you know what the estimate is based on.

Why you can trust our calculators

We think trust is earned through transparency, so we try to be open about how the site works:

• We show our sources. Pages link directly to the relevant GOV.UK and HMRC guidance so you can check the rules yourself.
• We don't gate anything. Every calculator is free, with no sign-up, paywall or email capture.
• We respect your privacy. Calculations run in your browser; we don't collect the salary, pension or savings figures you enter. See our privacy policy for full detail on cookies and advertising.
• We are independent. The site is funded by advertising, which keeps the tools free — but adverts never change the figures a calculator produces.

If you ever spot a figure that looks out of date or wrong, we genuinely want to hear about it. Accuracy is the whole point of the site, and reader corrections help us keep it that way. You can reach us any time through our contact page.