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. Although kilometres per hour is now used worldwide, miles per hour remains the standard unit for speed limits in the United States, the United Kingdom, Antigua & Barbuda and Puerto Rico, although the latter two use kilometres for distances.

Roadway usage

These include roads in the United Kingdom, the United States, and UK and US territories; American Samoa, the Bahamas, Belize, British Virgin Islands, the Cayman Islands, Dominica, the Falkland Islands, Grenada, Guam, Myanmar, The N. Mariana Islands, Samoa, St. Lucia, St. Vincent & The Grenadines, St. Helena, St. Kitts & Nevis, Turks & Caicos Islands, the U.S. Virgin Islands, Antigua & Barbuda (although km are used for distance), and Puerto Rico (same as former).

Miles per hour are also used in the Canadian rail system. In some countries it may be used to express the speed of delivery of a ball in sporting events such as cricket, tennis and baseball.