About

Who this site is for

New business owners, sole traders, company directors and small business owners who need business finance explained in plain English. You do not need to know what Marginal Relief is or how dividend stacking works. The calculators handle the mechanics and the explanations tell you what the answer means.

Why it exists

Most people running a small business meet these numbers occasionally rather than daily. VAT on an invoice, the tax on a good year's profit, whether a hire is affordable, what price gives a sensible margin. The information exists, but it is usually written for accountants or buried in guidance that assumes you already understand the terms.

Calculations make those decisions concrete. Seeing that a £35,000 salary really costs £40,550, or that a 50% markup is only a 33% margin, tells you more than a page of theory.

How the figures are produced

• Results come from deterministic software, fixed formulas written in code, not from generative AI. The same inputs always produce the same answer.
• Statutory calculators use published UK rates, held centrally and versioned by tax year, so a page can be updated without its address ever changing.
• Every calculator has automated tests, including tests at the exact points where rates and thresholds change.
• The workings are shown on each page so you can check them, and sources are linked where statutory rates are involved.

More detail is on the methodology page.

Who operates the site

BusinessCalculator.co.uk is operated by Bizworks Online Limited, a company registered in England and Wales (company number 11958108).

Registered office: The Studio, Brentmoor Road, Woking, Surrey, GU24 9NE. Email: info@businesscalculator.co.uk. More ways to reach us are on the contact page.

Important

This site provides information and estimates, not accounting, tax, legal or financial advice, and it is not connected with or endorsed by HMRC. We take care over the calculations, but you should confirm anything that materially affects your business with a qualified accountant or adviser.