Miles per hour be used to express the speed of delivery of a ball in sporting events such as cricket, tennis and baseball. Miles per hour Miles per hour (abbreviated mph, MPH or mi/h) is an imperial and United States customary unit of speed expressing the number of statute miles covered in one hour. It is used in the United States, United Kingdom and many Commonwealth nations, particularly in the Caribbean region. Speed limits and road traffic speeds are given in miles per hour in the following jurisdictions (elsewhere kilometers per hour are used): Road traffic speeds in other countries are indicated in
Kilometres per hour Kilometres per hour The kilometre per hour (American English: kilometer per hour) is a unit of speed, expressing the number of kilometres travelled in one hour. Internationally, km/h is the most commonly used unit of speed on traffic signs and speedometers. Although the metre was formally defined in 1799, the term "kilometres per hour" did not come into immediate use – the myriametre () and myriametre per hour were preferred to kilometres and kilometres per hour. In 1802 the term ""myriamètres par heure"" appeared in French literature and many French maps printed in the first half of the nineteenth century