About us

About TyreCalc

TyreCalc is a free library of car, tyre and fuel calculators — decode any tyre size, compare sizes side by side, check speedometer error, work out fuel cost and MPG, compare EV vs petrol running costs, and check towing and gear ratios.

What we do

Every tool on this site answers one practical question with the numbers you already have: the size stamped on your tyre sidewall, your car's MPG, the price at the pump. There are 32 tools, and every one of them runs entirely in your browser — nothing you type is sent to a server, and nothing costs anything. No sign-up, no account, no paywall.

The guides go deeper than the tools. Each one is 1,200+ words and works the maths out in full: what each marking on a tyre means, how a size change moves your speedometer, what a trip really costs in fuel, and what a tyre really costs per mile once wear is counted. Where a number comes from a published source, we say so; where it is an estimate, we label it one.

What we are not

TyreCalc is not a tyre fitter, a garage or a manufacturer, and nothing on this site is a safety approval or a fitment guarantee. A calculation that says a size is “within ±3%” is a diameter check — it does not mean the tyre clears your arches, matches your load index, or is legal on your car. Always check the size on your door-jamb placard and in your owner's manual, and consult a tyre professional before fitting a different size. Read the full Disclaimer.

How the site pays for itself

TyreCalc is free to use. The site is supported by advertising and by affiliate links to tyre and auto retailers — if you buy through one of those links, we may earn a commission at no extra cost to you. Affiliate links never change a calculation or a recommendation. See our Affiliate Disclosure and Editorial Policy.

Contact

Questions, corrections or a tool you would like us to add? Write to hello@tyrecalc.com or use the contact page.