Kilometer per Hour to Mile per Hour Conversion

Convert between Kilometer per Hour and Mile per Hour quickly and accurately.

km/h
mph

How to Convert Kilometer per Hour to Mile per Hour

Conversion Formula

1 km/h = 0.621 mph
1 mph = 1.609 km/h

Example

Convert 15 km/h to mph:

15 km/h = 15 × 0.621 mph = 9.321 mph

Unit Information

Learn about the speed units you're converting between

Kilometer per Hour

km/h

Definition

The kilometer per hour is a unit of speed expressing the number of kilometers traveled in one hour. It is commonly used for measuring vehicle speeds, wind speeds, and general transportation velocities in most countries worldwide, except the United States.

History/Origin

Kilometer per hour became widely adopted with the metric system in the 19th century, particularly in Europe and other metric countries. It replaced various regional speed measurements and became the standard for road signs, speedometers, and official speed limits.

Current Use

Kilometer per hour is the primary speed unit for road traffic, aviation, maritime navigation, and weather reporting in metric countries. It is used on speedometers, road signs, weather forecasts, and in transportation planning and safety regulations.

Multiplier

0.278

Offset

0

Mile per Hour

mph

Definition

The mile per hour is a unit of speed expressing the number of statute miles traveled in one hour. It is primarily used in the United States, United Kingdom, and other countries that have not fully adopted the metric system for everyday measurements.

History/Origin

Mile per hour has its origins in the British Imperial system and was widely used in the British Empire. It became the standard speed unit in the United States and remains the primary unit for road traffic, aviation, and weather reporting in these countries.

Current Use

Mile per hour is used for speed limits, speedometers, weather reports, and aviation in the US, UK, and other imperial system countries. It is also commonly used in sports, particularly in motorsports and athletics in these regions.

Multiplier

0.447

Offset

0

Kilometer per Hour to Mile per Hour Conversion Table

Kilometer per Hour [km/h] Mile per Hour [mph]
1 km/h 0.621371 mph
10 km/h 6.213712 mph
25 km/h 15.53428 mph
50 km/h 31.06856 mph
100 km/h 62.137119 mph
0 km/h 0E+0 mph
-10 km/h -6.213712 mph
-40 km/h -24.854848 mph

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