About the Speed Converter
Speed limits, weather reports, running apps and flight data each pick their own unit, so translating between them is a daily annoyance. This tool moves values across metres per second, kilometres per hour, miles per hour, feet per second, knots, Mach and the speed of light.
Knots matter in aviation and sailing. One knot is one nautical mile per hour, which is exactly 1852 metres in 3600 seconds, or about 0.5144 metres per second. Mach is taken at sea level standard conditions of 340.29 metres per second, and it is worth remembering that the real figure falls as air gets colder with altitude, so Mach numbers quoted for cruising airliners use a different reference.
The familiar pair of kilometres per hour to miles per hour is preselected, and the ratio 0.62137119 is printed with the result so you can drop it straight into code. Enter one speed per line to convert a whole set of readings. Speed is distance divided by time, so when you only need one half of that the Length Converter and Time Converter handle the pieces on their own.
How to use
- Enter one speed per line.
- Pick the unit you have and the unit you want.
- Read the converted speeds and the printed ratio.
- Copy the result.
Common questions
- What is 100 km/h in mph?
- About 62.14 mph. The exact factor is 0.62137119 miles per kilometre.
- How fast is one knot?
- One knot is 1.852 kilometres per hour, which is roughly 1.15 mph.
- Is Mach a fixed speed?
- No. It depends on air temperature. This tool uses the sea level reference of 340.29 metres per second.
- Can I convert a running pace?
- Not directly. A pace such as minutes per kilometre is the reciprocal of speed, so divide 60 by your speed in km/h to get it.