Convert kilometers per hour to miles per hour

Enter the number of kilometers per hour you want to convert to miles per hour in the text box below. The conversion to speed in miles per hour will update as you type.

Answer: 0.6214
kilometers per hour (km/h)
{"answerString":"0.621","answerSymbol":"miles per hour"}
1 kilometers per hour = 0.621 miles per hour

Precise decimal and fraction answers

The conversion in miles per hour rounded to six significant decimal places is 1 km/h = 0.621371 mph. The precise fraction answer is 1006/1619 mph.

Decimal Precision

Conversion from one to ten decimal places

  • 1 km/h = 0.6 mph
  • 1 km/h = 0.62 mph
  • 1 km/h = 0.621 mph
  • 1 km/h = 0.6214 mph
  • 1 km/h = 0.62137 mph
  • 1 km/h = 0.621371 mph
  • 1 km/h = 0.6213712 mph
  • 1 km/h = 0.62137119 mph
  • 1 km/h = 0.621371192 mph
  • 1 km/h = 0.6213711922 mph

How many miles per hour is a kilometer per hour?

A kilometer per hour is slower than a mile per hour. 0.621 miles per hour is the same velocity as one kilometer per hour. A kilometer per hour is 62.14% the velocity a mile per hour. An object moving at a mile per hour is 60.93% faster than an object traveling at one kilometer per hour.

Kilometers per hour to miles per hour conversion factor and formulas


The conversion factor between kilometers per hour and miles per hour is 1.609. This represents the ratio of kilometers per hour per one mile per hour. To calculate the value in miles per hour, we can either divide by the conversion factor or multiply by its inverse.


To convert from kilometers per hour to miles per hour, divide kilometers per hour by 1.609.
The formula is expressed as:
km/h ÷ 1.609 = mph


Alternatively we can multiply by the inverse conversion factor to get the same result.
The inverse of 1.609 is 1/1.609 or 0.621. To convert from kilometers per hour to miles per hour, multiply kilometers per hour by 0.621.
The formula is expressed as:
km/h × 0.621 = mph

About this conversion

Converting kilometers per hour to miles per hour is a conversion between units from separate unit systems - kilometers per hour are metric (SI) defined units while miles per hour are US Customary / UK Imperial .

About Kilometers per hour

SI Unit

Within the SI (metric) system of measurement, a kilometer per hour (km/h) is the distance traveled in one hour as measured in kilometers (1,000 meters). It is commonly used as measurement of velocity over geographic distances. Kilometers per hour are commonly used to measure vehicle speed and speed limits. The official SI symbol is km/h, however kph and km/hr are also used.

About Miles per hour

Customary/Imperial Unit

Miles per hour is a velocity measurement within the US/UK Imperial systems. It is defined as the number of miles traveled in one hour. MPH is frequently used for measurement and regulation of vehicle speed limits in the US, UK and many British dependencies. The common symbols for miles per hour are mph, MPH or mi/hr.

Reverse this conversion

Convert from miles per hour to kilometers per hour instead.

1 kilometers per hour to other speed units


  • 1 km/h = 1 km/h


  • 1 km/h = 0.621 mph
  • 1 km/h = 0.54 kn

References and Citations

  1. International Bureau of Weights and Measures (BIPM) The International System of Units (SI)
  2. National Institute of Standards and Technology (NIST) General Tables of Units of Measurement

Kilometers per hour to miles per hour conversion table

km/h mph
1 km/h 0.621 mph
2 km/h 1.243 mph
3 km/h 1.864 mph
4 km/h 2.485 mph
5 km/h 3.107 mph
6 km/h 3.728 mph
7 km/h 4.35 mph
8 km/h 4.971 mph
9 km/h 5.592 mph
10 km/h 6.214 mph
km/h mph
20 km/h 12.427 mph
30 km/h 18.641 mph
40 km/h 24.855 mph
50 km/h 31.069 mph
60 km/h 37.282 mph
70 km/h 43.496 mph
80 km/h 49.71 mph
90 km/h 55.923 mph
100 km/h 62.137 mph
1,000 km/h 621.371 mph

More km/h to mph conversions

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