Speed input
Unit converter
Speed Converter
Convert mph, km/h, m/s, ft/s, knots, Mach and running pace instantly. Useful for driving, cycling, running, aviation, shipping, physics and weather reports.
road + air + sea
All results
Speed conversion results
Miles per hourmph
Kilometers per hourkm/h
Meters per secondm/s
Feet per secondft/s
Knotskn
MachMach
Centimeters per secondcm/s
Pace per kilometermin/km
Pace per milemin/mi
Speed conversion formulas
km/h = mph × 1.609344Road speed conversion between US/UK and metric signs.
m/s = km/h ÷ 3.6Physics and engineering speed conversion.
kn = km/h ÷ 1.852Marine and aviation speed conversion.
Mach = m/s ÷ 343Approximate Mach number using 343 m/s at sea level and 20 °C.
Speed conversion reference table
| Unit | Equals | Typical use |
|---|---|---|
| 1 mph | 1.609344 km/h | Road speed in the US and UK |
| 1 km/h | 0.6213711922 mph | Road speed in metric countries |
| 1 m/s | 3.6 km/h | Physics, wind and engineering |
| 1 ft/s | 0.3048 m/s | Engineering and ballistics |
| 1 kn | 1.852 km/h | Ships, aircraft and weather |
| Mach 1 | ≈ 343 m/s | Aviation and acoustics |
Common speed examples
Highway speed60 mph is about 96.56 km/h for road signs and travel planning.
Running pace12 km/h equals a 5:00 min/km pace or about 8:03 min/mile.
Wind reports15 m/s equals 54 km/h or about 29.16 knots.
Marine speed20 knots equals 37.04 km/h or about 23.02 mph.
Popular speed conversions
Speed converter FAQ
How many kilometers per hour are in one mile per hour?
One mile per hour equals exactly 1.609344 kilometers per hour.
How many miles per hour are in 100 km/h?
100 km/h equals approximately 62.137119 mph.
How is running pace calculated?
Pace is the time needed to cover one kilometer or one mile at the selected speed.
What speed is Mach 1?
This converter uses 343 m/s as an approximate Mach 1 value at sea level and 20 °C; actual speed varies with temperature and altitude.