Kilometres per hour

Speed limit in km/h on a road in Denmark.

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

Speed limit units on traffic signs around the world:
  Miles per hour (mph)
  Both
  No speed limit units

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