Kilometres per hour
Kilometres per hour is a unit of measurement, which measures speed or velocity. The unit symbol is km/h or km·h−1. By definition, an object travelling at a speed of 1 km/h in a straight line for 1 hour moves 1 kilometre. The unit is the most commonly used unit of speed worldwide, more common than the SI unit of speed, metres per second.
- 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)