Speed Converter

A speed converter changes a velocity from one unit to another across the systems used for driving, running, science, and navigation. This free tool handles the four most common units: kilometers per hour (km/h) and miles per hour (mph) for road speed, meters per second (m/s) for physics and athletics, and knots for marine and aviation use. Enter a value, pick the unit you have and the unit you want, and the result updates instantly. The conversions are built on exact definitions, so they match official standards. A mile is exactly 1609.344 meters, which makes 100 km/h about 62.1 mph and 60 mph about 96.6 km/h. Meters per second relate to km/h by the simple factor 3.6, so 10 m/s equals 36 km/h, a handy figure for athletics and physics. A knot is one nautical mile per hour, where a nautical mile is exactly 1852 meters, making a knot about 1.852 km/h or 1.151 mph; knots are used at sea and in the air because a nautical mile corresponds to one minute of latitude. Real-world uses are everywhere: converting a foreign speed limit while driving abroad, comparing a running pace across km/h, mph, and m/s, reading a boat or aircraft instrument in knots, or converting physics problems between m/s and km/h. Because the underlying length and time factors are exact, the only rounding happens on the displayed answer. Everything runs locally in your browser, so it is fast, private, and works offline once loaded.