A miles per hour calculator, or MPH calculator, determines the average miles per hour based on the amount of time it takes to travel a certain number of miles. Miles per hour is a U.S. customary unit.
The miles per hour measurement is also part of the imperial unit system and it is the standard speed unit to set speed limits in the United States, the United Kingdom and their respective territories. The unit is indistinctly abbreviated as MPH, mph and mi/h.
The word mile derives from the Latin word "m?lia," which means "thousand." Romans used the words "mille passus" to refer to the distance of 1,000 paces of two steps each, which is known as the Roman Mile.