Who we are
CalcBudget is a free website of UK money calculators and plain-English guides. It is owned and operated by The AI Barn, The AI Barn, 124 City Road, London, EC1V 2NX, United Kingdom. You can contact us at hello@theaibarn.com.
Why the site exists
Many everyday money questions come down to a calculation: how much of a pay rise you will actually keep, how much Stamp Duty a purchase will cost, what a loan will cost over five years rather than three, or how long it will take to build an emergency fund. The numbers are often simple once you know the rules, but the rules are spread across many official pages and are easy to get wrong.
CalcBudget brings those calculations together in one place, for UK users. Each calculator shows the result and also explains how it was reached: the rates and thresholds used, worked examples you can check, the assumptions behind the figure and the things it does not cover. Our guides explain the wider topic, such as budgeting, saving, borrowing and paying off debt, with links to official sources so you can check the detail yourself.
The site is free to use. It is funded by advertising, shown through Google AdSense. Advertisers do not decide what we write, and we do not accept payment to recommend products.
How we check our calculators
Where a calculator depends on a tax rule or official threshold, we take the rates directly from GOV.UK and HMRC and link to the source page from the calculator. Before publishing a change, we test the calculator against worked examples, including examples published on GOV.UK where they exist, and we check the results by hand.
Tax rates and allowances usually change at the start of the tax year on 6 April, and sometimes after announcements such as the Budget. We review every tax-related calculator each April, and whenever a relevant change is announced, and record the tax year and review date on each page. Our methodology explains the approach in more detail, and our editorial policy explains how we write and update guides.
What CalcBudget is not
CalcBudget provides general information and estimates for planning. It is not financial, tax, mortgage, legal or investment advice, and it is not authorised or regulated by the Financial Conduct Authority. Calculator results cannot take account of every detail of your circumstances. For important decisions, check figures with HMRC, GOV.UK, your lender or a qualified, regulated adviser. Free, impartial guidance is also available from MoneyHelper, which is backed by the government.
Spotted a problem?
If you think a calculator gives the wrong answer or a guide is out of date, please email hello@theaibarn.com with the page and the figures you used. We investigate every report and explain significant changes in line with our corrections policy.
Last updated October 2026.