Speed Converter
km/h, mph, m/s, knots, ft/s — and Mach.
100 km/h equals
62.1371 mph
| Unit | Value |
|---|---|
| Meters per second | 27.7778 m/s |
| Miles per hour | 62.1371 mph |
| Knots (nautical mph) | 53.9957 knots |
| Feet per second | 91.1344 ft/s |
| Mach (speed of sound) | 0.081 mach |
About this calc
Convert speeds between every common unit: metric, imperial, nautical, aviation. Includes Mach (speed of sound at 20°C).
FAQ
- How do I convert km/h to mph?
- Multiply by 0.621371. Example: 100 km/h ≈ 62.14 mph.
- How fast is Mach 1?
- About 343 m/s or 1,235 km/h (767 mph) at sea level, 20°C. It drops at altitude because air temperature does.
- Why do ships use knots?
- One knot = one nautical mile per hour, and one nautical mile = one minute of latitude. It makes navigation math with charts much cleaner.