Speed Converter

How Speed Converter works

Convert speed between kilometres per hour, miles per hour, metres per second, knots and feet per second. Everything happens inside this page: the tool reads your input, runs the calculation or conversion locally, and hands the result back to you. Nothing is transmitted, because there is no backend to transmit it to.

That design choice is deliberate. Most free tool sites upload your files to a server, process them there, and quietly keep a copy. Toolcin cannot do that — the site is a set of static files. If your connection dropped the moment the page finished loading, every tool would still work.

Five units, one metre per second

Every speed here is defined against metres per second, which is why converting between km/h and mph passes through it. The factors are exact: 1 km/h is 0.277778 m/s and 1 mph is 0.44704 m/s.

The knot is the odd one — 0.514444 m/s, because it is one nautical mile per hour, and a nautical mile is 1,852 m rather than 1,609.

The 3.6 shortcut

km/h to m/s is exactly divide by 3.6, and m/s to km/h is multiply by 3.6. That is worth memorising because it comes up in physics homework and in weather forecasts constantly.

mph to km/h is multiply by 1.609344 — the same factor as miles to kilometres, because both are distance per hour.

Wind, water and roads

Weather uses knots at sea, km/h on land in most countries and mph in the US and UK. A 25-knot wind is 46 km/h, which is a strong breeze rather than a gale — the unit changes how alarming the number sounds.

Vehicle speedometers over-read by design, typically 2–5%, so the converted figure is more accurate than the dashboard.

Good to know

• Works offline once loaded, including on flights and in locked-down networks.
• No file size limit beyond your device's own memory.
• Free to use, with no account and no usage counter.
• Results are produced locally, so they are not logged or shared with anyone.

Questions