1 Kilometer per Hour equals 0.621371 Miles per Hour.
| Kilometer per Hour (km/h) | Mile per Hour (mph) |
|---|---|
| 0.001 km/h | 0.000621371 mph |
| 0.01 km/h | 0.00621371 mph |
| 0.1 km/h | 0.0621371 mph |
| 1 km/h | 0.621371 mph |
| 2 km/h | 1.24274 mph |
| 5 km/h | 3.10686 mph |
| 10 km/h | 6.21371 mph |
| 25 km/h | 15.5343 mph |
| 50 km/h | 31.0686 mph |
| 100 km/h | 62.1371 mph |
| 500 km/h | 310.686 mph |
| 1,000 km/h | 621.371 mph |
To convert Kilometers per Hour to Miles per Hour, multiply the value by 0.621371. This factor comes from the ratio of the two units' definitions: one Kilometer per Hour equals 0.621371 Miles per Hour.
For example: 1 Kilometer per Hour = 0.621371 Miles per Hour, and 10 Kilometers per Hour = 6.21371 Miles per Hour.
To convert in the reverse direction — from Miles per Hour to Kilometers per Hour — multiply by 1.60934.
The kilometer per hour (km/h), sometimes written as kph, is the standard unit for vehicle speeds on roads in most countries that use the metric system. Speed limits throughout Europe, Asia, Africa, South America, and Oceania are posted in km/h: 50 km/h in towns, 100–130 km/h on highways. Automobile speedometers in these countries display km/h as the primary scale, and traffic law specifies limits in km/h.
A brisk walking pace is about 5 km/h; cycling on flat terrain is typically 15–25 km/h; a car cruising on a motorway might travel at 100–130 km/h; a commercial jet cruises at 850–920 km/h. These benchmarks make km/h intuitive for human-scale transportation. Converting to m/s is straightforward: divide by 3.6 (since 1 km/h = 1000/3600 m/s = 1/3.6 m/s).
In aviation, km/h appears on aircraft airspeed indicators in countries that use metric units for aviation, though internationally, knots are the standard for navigation. Typhoon and hurricane wind speeds are routinely broadcast in km/h by meteorological agencies in Asia and the Pacific. Train speeds — particularly for high-speed rail — are prominently communicated in km/h, with the Shanghai Maglev reaching 431 km/h and the Shinkansen networks operating at 240–320 km/h.
Miles per hour (mph or mi/h) is the standard speed unit for road transport in the United States and the United Kingdom. All US and UK speed limit signs, speedometers, and traffic law enforcement use mph. A speed limit of 55 mph (about 89 km/h) on a US freeway and a limit of 70 mph (113 km/h) on a British motorway are familiar to drivers in those countries. Shipping and weather services in the US also use mph for wind speeds and storm movement.
In athletics, miles per hour provides intuitive benchmarks: a casual jogger runs at about 5–6 mph; a competitive runner might race a 5K at 10–11 mph; Usain Bolt's world record 100m sprint averaged just over 23 mph (37.6 km/h). Baseball pitch speeds are reported in mph — a major league fastball at 95+ mph is an elite pitch. American football field-goal kicking distances and punting trajectories are analyzed with speed in mph.
Converting between mph and km/h is a common practical need: mph × 1.609 ≈ km/h, or more roughly, mph × 1.6. A speed of 60 mph is almost exactly 96.6 km/h — close enough to 100 km/h that many drivers use 60 mph ≈ 100 km/h as a mental shorthand when driving across the US-Canada border. The exact multiplier 1.609344 comes from the definition of the statute mile as exactly 1,609.344 meters.
1 Kilometer per Hour equals 0.621371 Miles per Hour.
To convert Kilometers per Hour to Miles per Hour, multiply by 0.621371. For example, 1 Kilometer per Hour = 0.621371 Miles per Hour.
1 Mile per Hour equals 1.60934 Kilometers per Hour.