Speed Converter

About the Speed

This speed converter converts between metres per second, kilometres per hour, miles per hour, knots, and feet per second — the units used on roads, in weather reports, and in aviation and maritime. Speed is one of those units you meet in dramatically different forms depending on the context. On the road: a kilometre per hour is the standard in most of the world, while mph rules the US and the UK still use miles per hour on road signs. 1 mph = 1.60934 km/h, so a 70 mph motorway limit is about 113 km/h. To convert mph to km/h, multiply by 1.609; to convert km/h to mph, divide by 1.609 (or multiply by 0.6214). A 100 km/h limit is about 62 mph. Knots are the unit of speed used in aviation, maritime, and meteorology. A knot is one nautical mile per hour, equal to 1.852 km/h or 1.151 mph. Wind speeds in marine and aviation forecasts are usually given in knots, which is why pilots and sailors think in knots rather than mph or km/h. The reason a nautical mile exists is that it corresponds to one minute of latitude on the globe, making navigation by chart natural. Metres per second is the SI unit and is used in physics, weather reports, and engineering — a wind speed of 10 m/s is about 36 km/h or 22 mph. Feet per second is more common in US engineering contexts. The converter moves freely between all of them, giving you the exact result in real time. Whether you are converting car speed limits, checking wind for a day sailing, or comparing an aeroplane's speed, this tool handles it instantly.