Speed Converter
1 m/s = 3.6 km/h
About the speed category
How fast something moves: driving, running, wind, and data download marketing.
You will reach for these conversions when driving abroad: speed limit signs in a unit your speedometer does not show prominently, or understanding running paces quoted in minutes per mile vs per km.
- A common highway limit: 100 km/h is about 62 mph
- City limit: 30 km/h is about 19 mph
- A brisk run: 5 m/s is 18 km/h, or about 11 mph
Popular speed conversions
Common mistakes
- UK road signs are in mph while fuel is sold in liters; mixed system
- Confusing km/h with mph in a 30-vs-50 context nearly doubles or halves the real speed
Frequently asked questions
Which speed units does this converter support?
6 units: Meter per Second, Kilometer per Hour, Mile per Hour, Foot per Second, Knot, Mach (Sea Level). All conversions run locally in your browser, nothing is sent to a server.
How accurate are the speed conversions?
All factors follow the official SI definitions and internationally agreed standards. Results are shown with up to 8 significant digits, which is far beyond the precision of everyday measurements.
Is this converter free?
Yes, completely free and unlimited, supported by ads. No app install, no sign-up.