Kilometres per hour

The kilometre per hour or kilometer per hour (symbol: km/h, km h-1 or km·h−1) is a unit of speed or velocity. 

Definition
By definition, an object travelling at a speed of 1 km/h in a straight line for one hour moves one kilometre. The unit is the most commonly used unit of speed worldwide, more common than the SI unit of speed, metre per second (m/s or m s-1).

Conversions

 3.6 km/h ≡ 1 m/s, the SI unit of speed, metre per second
 1 km/h ≈ 0.277 78 m/s
 1 km/h ≈ 0.621 37 mph ≈ 0.911 34 feet per second
 1 knot ≡ 1.852 km/h (exactly)
 1 mile = 1.609344 km (~1.61 km)
 n km/h ≈ (1.61 * n) mph (where n is a quantity of speed in km/h)
 1 mph = ~1.6 km/h

Related pages

 Kinematics

Category:Physics
Category:Units of velocity