Speed Converters
The speed (commonly referred to as v) is a measure of how fast something is travelling. The most common units of speed are metres per second (m/s), kilometres per hour (km/h) and miles per hour (mph). In a typical car journey the speed of the car will change. The distance divided by the time will calculate the average speed of the car.
Time Measurement
The SI unit of speed is the metre per second, but the most common unit of speed in everyday usage is the kilometre per hour or, in the US and the UK, miles per hour. For air and marine travel the knot is commonly used.
The speed of an object is how far the object travels in one unit of time. The formula for speed is:
Speed = 

The speed of an object is the magnitude of the change of its position; it is thus a scalar quantity.[1] The average speed of an object in an interval of time is the distance travelled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as the duration of the time interval approaches zero.