Miles per hour to Kilometers per hour Converter

Use this converter to easily convert between Miles per hour and Kilometers per hour (mph to kmph / kmh).

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How many Kilometers per hour equal one Mile per hour?

A speed of exactly 1.609344 kilometers per hour equals one mile per hour, and this follows from the definition of a mile as 5280 feet, of a feet as 0.3044 meters, and of a kilometer as 1,000 meters and performing the necessary mathematical operations. These are internationally agreed upon unit definitions established by treaty in 1959. The internationally recognized symbol for mile is "mi", and "km" for kilometer and "per hour" is usually abbreviated to "ph" leading to "mph" and "kmph", but some people do use "kph" instead.

Difference between Miles per hour and Kilometers per hour

The mile and the kilometer are both units used for measuring distances of comparable magnitude, e.g. distances one would travel by car, truck, train, or plane. When talking about speed these are suffixed by "per hour" to indicate the distance covered in a unit of time. The difference between the to units is that mph is based on the mile, which is a part of the imperial system while kmph is based on the kilometer which is a part of the modern metric system. The kilometer is used in most countries in the world, while miles are only used in several countries like the US and the UK, and their territories.

Miles have a long history, for example we know of the Roman mile back in the days of the Roman Empire. At different times and in different places there were different definitions of the mile and it equaled different distances, e.g. Italian mile, English mile, Scot mile, Irish mile.

How to convert Miles per hour to Kilometers per hour

For any speed measurement unit we need to account for both the time dimension and the distance dimension, but since the time unit is hours in both cases, we can ignore. Thus, to convert miles per hour to kilometers per hour simply multiply the speed in mph by 1.609344. This mathematical operation is usually hard to do, so calculators are employed when one needs to do a precise conversion. The conversion of speed in miles per hour to a speed in kilometers per hour is easier with our online converter above, which also have a quick copy function.

Miles per hour to km per hour conversion example

Sample task: convert 100 miles per hour to kilometers per hour. Solution:

Formula:
mph * 1.609344 = kmph
Calculation:
100 mph * 1.6093 = 160.9344 kmph
End result:
100 mph is equal to 160.9344 kmph

Mph to kph conversion table

mph to km/h conversion table
mph km/h
1 mph 1.609344 km/h
2 mph 3.218688 km/h
3 mph 4.828032 km/h
4 mph 6.437376 km/h
5 mph 8.046720 km/h
6 mph 9.656064 km/h
7 mph 11.265408 km/h
8 mph 12.874752 km/h
9 mph 14.484096 km/h
10 mph 16.093440 km/h
20 mph 32.186880 km/h
30 mph 48.280320 km/h
40 mph 64.373760 km/h
50 mph 80.467200 km/h
60 mph 96.560640 km/h
70 mph 112.654080 km/h
80 mph 128.747520 km/h
90 mph 144.840960 km/h
100 mph 160.934400 km/h
200 mph 321.868800 km/h
300 mph 482.803200 km/h
400 mph 643.737600 km/h
500 mph 804.672000 km/h
600 mph 965.606400 km/h
700 mph 1,126.540800 km/h
800 mph 1,287.475200 km/h
900 mph 1,448.409600 km/h
1,000 mph 1,609.344000 km/h

References:

[1] NIST Special Publication 330 (2008) - "The International System of Units (SI)", edited by Barry N.Taylor and Ambler Thompson

[2] International Organization for Standardization (1993). ISO Standards Handbook: Quantities and units (3rd edition). Geneva: ISO. ISBN 92-67-10185-4.

Cite this converter & page

If you'd like to cite this online converter resource and information as provided on the page, you can use the following citation:
Georgiev G.Z., "Mph to Kmh Converter", [online] Available at: https://www.gigacalculator.com/converters/convert-mph-to-kmph.php URL [Accessed Date: 18 Nov, 2019].