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Convert mph to km/h

Instant speed converter mph to km/h

Simply enter the speed in miles per hour or kilometer(s) per hour to have the free live conversion.

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Formula for converting mph to km/h

Consider that each mile unit equals to 1.609344 kilometers. Calculating the speed which, when based on the same time, will give the same conversion multiple.

Convert from mph to km/h

Mile per hour multiplied by 1.609344 equals kilometer per hour

Mile per hour divided by 0.621371 equal kilometer per hour


Take for example a car traveling at a speed of 80 mph, what will be its speed in km/h using the conversion method by multiplication?

80 mph x 1.609344 = 128.74752 or when rounded to 128.75 km/h

Convert from km/h to mph

Kilometer per hour multiplied by 0.621371 equals Mile per hour

Kilometer per hour divided by 1.609344 equal Mile per hour


Take for example a car traveling at a speed of 150 km/h, what will be its speed in mph using the method of conversion by division?

150 km/h / 1.609344 = 93.2056788 or when rounded to 93.21 mph

How much is 1 mph in km/h

1 mph = 1.609344 km/h

How much is 1 km/h in mph

1 km/h = 0.621371 mph

The kilometer per hour

As the name suggests, the kilometer per hour is used to measure the number of kilometers traveled in an hour. This unit of measurement for speed is a multiple of the meter per second within the international system of units.

This unit is often referred to as kilometer-hour, kilometre per hour or used as an abbreviation km/h, kph,kmph, km/hr.

Speed of sound

The speed of sound is often expressed in meters per second but can also be converted to kilometers per hour. This speed of propagation of sound waves is very variable and depends mainly on the temperature as well as the density (density) of the medium (such as air, water, gas) in which it is taken.

In air at 15 degrees celsius, its speed is about 340 m / s or 1224 km/h.

In water it is propagated almost 4.5 times faster, i.e. 1500 m / s (in sea water) or 5400 km/h.

Our speed of sound data comes from the Cyberphon (Université Lumière Lyon CNRS * French version) .

Speed of light

The speed of light is regularly indicated in meter per second but can also easily be converted to kilometer per hour. This speed, being the fastest of all forms in the universe, is variable and depends essentially on the refractive index of the medium in which it enters or propagates.

In a vacuum its speed is 299,792,458 m / s or 1,079,252,848.8 km/h.

Our data concerning this speed are taken from the Wikipedia website .


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