Mile per hour (mph) - Unit Information & Conversion

Symbol:mph
Plural:miles per hour
Category:Speed

What is a Mile per hour?

Definition

Miles per hour (mph, MPH, or mi/h) is an imperial and US customary unit of speed expressing the number of statute miles traveled in one hour.

History

Miles per hour became prominent with the rise of automotive transportation in countries using the imperial system, particularly the United Kingdom and the United States. It provided a practical measure for road travel speeds and regulations.

Common Uses

  • Road Traffic (US/UK): The standard unit for speed limits and vehicle speeds (speedometers) in the United States, United Kingdom, and a few other countries.
  • Rail Transport (US/UK): Often used for train speeds in these same countries.
  • Meteorology (Informal): Sometimes used informally in the US/UK for wind speed in public weather reports, though knots or m/s are preferred in official meteorological contexts.
  • Sports: Used in some sports like baseball (pitch speed) and sometimes informally in running or cycling in relevant countries.

Unit FAQs

Which countries use mph for speed limits?

Miles per hour is primarily used for road speed limits in the United States, the United Kingdom, and some Caribbean nations.

Is mph an SI unit?

No, mph is part of the imperial and US customary systems. The SI unit for speed is meters per second (m/s).

How do you convert mph to km/h?

Multiply the speed in mph by 1.60934. So, 60 mph is approximately 96.6 km/h.

How do you convert mph to ft/s?

Multiply the speed in mph by 1.46667. So, 60 mph is approximately 88 ft/s.

Mile per hour Conversion Formulas

To Meter per second:

1 mph = 0.44704 m/s
Example: 5 miles per hour = 2.2352 meters per second

To Kilometer per hour:

1 mph = 1.609344 km/h
Example: 5 miles per hour = 8.04672 kilometers per hour

To Foot per second:

1 mph = 1.466667 ft/s
Example: 5 miles per hour = 7.333333 feet per second

To Knot:

1 mph = 0.868976 kn
Example: 5 miles per hour = 4.344881 knots

To Mach number:

1 mph = 0.001303 Mach
Example: 5 miles per hour = 0.006517 Mach numbers

To Speed of light:

1 mph = 1.4912e-9 c
Example: 5 miles per hour = 7.4558e-9 speed of light

Convert Mile per hour

Need to convert Mile per hour to other speed units? Use our conversion tool.