Speedometer in MPH.

Miles per hour is a unit of speed, expressing the number of international miles covered per hour. It is commonly abbreviated in everyday use in the United States, the United Kingdom, and elsewhere to mph or MPH, although mi/h is sometimes used in technical publications.

The preferred unit for velocity is m·s−1. Speeds are often quoted in km/h especially in mainland Europe, Australia and elsewhere. Nautical and aeronautical applications usually favour the knot as a unit of speed: one knot is one nautical mile per hour.


1 mph is equal to:

  • 0.44704 m·s−1, the SI derived unit
  • 1.609344 kilometers per hour
  • 22/15 =1.4667 feet per second
  • approx. 0.868976 knots

When converting miles per hour to another unit of measurement, or vice versa, it helps a lot to know exactly how miles and hours are related to other units of distance and time, respectively. For example, 1 mile is equal to 5,280 feet, 1,760 yards, or 1,609 meters. Likewise, 1 hour is equal to 60 minutes, or 3,600 seconds.

Miles per hour is the unit used for speed limits on roads in the United Kingdom, United States and various other nations.

See Also[]

  • Kilometers per hour
  • Speed limits