About the Speed Converter
Speed limits, weather reports, sports telemetry and flight data all use different units, and the gap between them is big enough to matter: 100 km/h is 62 mph, and a 30 mph limit is a little under 50 km/h. This converter handles the six units you actually meet, including knots for sailing and aviation and mach for aircraft speeds.
Metres per second is the SI unit and the one physics problems expect, kilometres per hour dominates road signs outside the United States and the United Kingdom, and the knot survives because it equals one nautical mile per hour, which lines up with degrees of latitude on a chart. Mach is not a fixed speed: it is the ratio to the local speed of sound, and this tool uses the standard sea-level value of 340.29 m/s.
How to use the Speed Converter
- Enter the speed you want to convert.
- Pick the unit you have and the unit you want.
- Read the answer, or use the table to see the speed in all six units at once.