Speed Converter — 9 Units, Live Conversion
Type a value in any field and every other speed unit updates instantly. Kilometres per hour, miles per hour, metres per second, knots, Mach, and more — all in one place.
- 🚶Walking pace~1.4 m/s · ~5 km/h
- 🏃Running (sprint)~10 m/s · ~36 km/h
- 🚗Car (highway)~30 m/s · ~108 km/h
- 🚄High-speed train~83 m/s · ~298.8 km/h
- ✈️Commercial jet~250 m/s · ~900 km/h
- 🔊Speed of sound~343 m/s · ~1,235 km/h
- 🚀Escape velocity~11.186k m/s · ~40,270 km/h
- ✨Speed of light~299,792.458k m/s · ~1,079,252,849 km/h
How to use this tool
- 1Find the unit you know
Locate the input field for the speed unit you have — for example, km/h or mph. Or use a quick-preset button for common starting points.
- 2Type the value
Enter your number into the field. All 8 remaining unit fields update instantly as you type — no button click needed.
- 3Copy the result
Click the copy button next to any converted value to copy it to your clipboard. Use Clear All to reset everything.
Speed units explained
Everyday speed units
Most countries use kilometres per hour (km/h) for road speed limits and vehicle speedometers. The United States and United Kingdom use miles per hour (mph) for road signage. One mph equals 1.60934 km/h. Speed limits, GPS readings, and weather reports are the most common contexts where you need to convert between them.
Aviation and maritime
Pilots and sailors use knots (nautical miles per hour) because one nautical mile corresponds to one minute of latitude, making chart navigation simpler. Mach numbers express speed as a fraction of the speed of sound, which is critical for jet aircraft performance calculations. Mach 1 is roughly 1,235 km/h at sea level.
Scientific and engineering
The SI unit of speed is metres per second (m/s). It is used in physics, engineering, and weather forecasting (wind speed). Feet per second (ft/s) appears in US ballistics and some engineering contexts. The speed of light (approximately 299,792,458 m/s) serves as an absolute speed limit in physics.
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