Speed converter
Speed Converter – 6 Units, Exact Factors
1 mile per hour = 1.6093 kilometres per hour
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- 1 mph = 1.6093 km/h
- 5 mph = 8.0467 km/h
- 10 mph = 16.093 km/h
- 25 mph = 40.234 km/h
- Kilometres per hourkm/h
- Miles per hourmph
- Metres per secondm/s
- Knotskn
- Feet per secondft/s
- × speed of lightc
- Kilometres per hour1.6093km/h
- Miles per hour1mph
- Metres per second0.44704m/s
- Knots0.86898kn
- Feet per second1.4667ft/s
- × speed of lightc
About speed conversions
Convert driving, wind and running speeds. One mile per hour is exactly 0.44704 m/s.
Common speed conversions
Speed units explained
| Unit | System | Definition and notes |
|---|---|---|
| Kilometre per hour (km/h) | metric (non-SI) | 1 km/h ≈ 0.27777778 m/s |
| Mile per hour (mph) | US & imperial (identical) | 1 mph = 0.44704 m/s (exact)Defined as exactly 0.44704 m/s. |
| Metre per second (m/s) | SI (metric) | Base unit |
| Knot (kn) | other | 1 kn ≈ 0.51444444 m/sOne nautical mile per hour, about 0.5144 m/s. Used at sea and in aviation. |
| Foot per second (ft/s) | US & imperial (identical) | 1 ft/s = 0.3048 m/s (exact) |
| Speed of light (c) | other | 1 c = 299,792,458 m/s (exact)The speed of light in a vacuum: exactly 299,792,458 m/s. |
Miles per hour to kilometres per hour conversion table
| Miles per hour (mph) | Kilometres per hour (km/h) |
|---|---|
| 0.1 mph | 0.16093 km/h |
| 0.5 mph | 0.80467 km/h |
| 1 mph | 1.6093 km/h |
| 2 mph | 3.2187 km/h |
| 3 mph | 4.828 km/h |
| 4 mph | 6.4374 km/h |
| 5 mph | 8.0467 km/h |
| 6 mph | 9.6561 km/h |
| 7 mph | 11.265 km/h |
| 8 mph | 12.875 km/h |
| 9 mph | 14.484 km/h |
| 10 mph | 16.093 km/h |
| 15 mph | 24.14 km/h |
| 20 mph | 32.187 km/h |
| 25 mph | 40.234 km/h |
| 30 mph | 48.28 km/h |
| 40 mph | 64.374 km/h |
| 50 mph | 80.467 km/h |
| 75 mph | 120.7 km/h |
| 100 mph | 160.93 km/h |
| 250 mph | 402.34 km/h |
| 500 mph | 804.67 km/h |
| 1,000 mph | 1,609.3 km/h |
Frequently asked questions
Which speed units can I convert?
kilometres per hour (km/h), miles per hour (mph), metres per second (m/s), knots (kn), feet per second (ft/s), × speed of light (c).
How accurate are the results?
Every unit is stored with its exact defining factor (NIST SP 811, NIST Handbook 44 or the BIPM SI Brochure). Calculations use double-precision arithmetic and are rounded only for display, to 5 significant figures by default (trailing zeros dropped, so 1 km shows as 1000 m). You can choose Auto (up to 10 digits), fixed decimals or more significant figures, or switch to scientific or engineering notation.