Convert miles, inches, feet, kilometers and every unit of distance — instantly and free.
The world measures distance in two languages. Road signs, running races, property listings and TV screens all switch between miles, kilometers, feet and inches depending on the country — and the difference is never round. A mile is not 1.5 km, a foot is not 30 cm, and "close enough" fails the moment precision matters: a dart board, a door frame, a marathon route.
Each converter below runs instantly in your browser, with the exact formula, a conversion table and the mental shortcuts that make you faster than any calculator. No sign-up, no ads in the way — just the answer.
The most searched conversions here are miles to kilometers and inches to centimeters — the two places where daily life switches systems. Runners race in 5Ks, American DIY plans speak in feet, European road trips run in kilometers. Below you'll also find yards, nautical miles and millimeters, each with the same promise: type a value, get the exact answer, move on.
Are these converters really free? Yes — unlimited, no account, no paywall. CalculUnits is funded by non-intrusive ads only.
How accurate are the results? Every conversion uses the exact official factor from SI and NIST references, shown on each page so you can verify the math yourself.
Do my values leave my device? No — all calculations run in your browser. Nothing you type is ever sent anywhere.