Miles per Hour to Kilometers per Hour Converter
Enter a value below to convert miles per hour to km/h - one mile per hour is exactly 1.609344 km/h (1 km/h is about 0.6214 mph). For the reverse, use our kilometers per hour to miles per hour converter.
1 mph = 1.609344 km/h. Convert miles per hour to km/h. Need the reverse? See km/h to mph.
Mile per hour
- Definition
- A mile per hour (symbol: mph) is a unit of speed in the imperial and US customary systems, equal to one statute mile traveled in one hour. Since a mile is exactly 1,609.344 meters, 1 mph equals exactly 1.609344 km/h, or 0.44704 meters per second.
- History / origin
- The mile per hour grew out of the statute mile, a unit fixed in English law under Elizabeth I in 1593 at 5,280 feet. As road and rail travel spread, miles per hour became the natural way to state vehicle speeds in English-speaking countries, and it was carried onto speedometers and speed-limit signs.
- Current use
- Miles per hour is the standard road-speed unit in the United States and the United Kingdom, where speed limits, speedometers and weather wind speeds are quoted in mph. It is also used in a handful of other countries and territories that retain imperial road signage.
Kilometer per hour
- Definition
- A kilometer per hour (symbol: km/h) is a unit of speed expressing the number of kilometers traveled in one hour. It is the metric road-speed unit; 1 km/h equals exactly 0.2777... meters per second (1/3.6 m/s) and about 0.6214 mph.
- History / origin
- The kilometer per hour follows from the metre, defined under the metric system introduced in France in the 1790s, combined with the hour. As the metric system was adopted across Europe and beyond, km/h became the standard way to mark road speeds, replacing older local units.
- Current use
- Kilometer per hour is the legal speed unit on roads in most of the world, including continental Europe, Canada, Australia and Asia. Speed-limit signs, car speedometers and transport timetables in metric countries are given in km/h.
Mile per hour to kilometer per hour conversion table
| Mile per hour [mph] | Kilometer per hour [km/h] |
|---|---|
| 1 mph | 1.609344 km/h |
| 5 mph | 8.04672 km/h |
| 10 mph | 16.09344 km/h |
| 20 mph | 32.18688 km/h |
| 30 mph | 48.28032 km/h |
| 40 mph | 64.37376 km/h |
| 50 mph | 80.4672 km/h |
| 60 mph | 96.56064 km/h |
| 70 mph | 112.65408 km/h |
| 80 mph | 128.74752 km/h |
| 100 mph | 160.9344 km/h |
| 120 mph | 193.12128 km/h |
Popular mile per hour to kilometer per hour conversions
Common road and motorway speeds in km/h, rounded to two decimals - the mph values drivers look up most.
| Mile per hour [mph] | Kilometer per hour [km/h] |
|---|---|
| 20 mph | 32.19 km/h |
| 30 mph | 48.28 km/h |
| 40 mph | 64.37 km/h |
| 50 mph | 80.47 km/h |
| 60 mph | 96.56 km/h |
| 70 mph | 112.65 km/h |
| 80 mph | 128.75 km/h |
| 90 mph | 144.84 km/h |
| 100 mph | 160.93 km/h |
| 120 mph | 193.12 km/h |
How to convert miles per hour to kilometers per hour
To convert miles per hour to kilometers per hour, multiply the number of miles per hour by 1.609344. For example, 60 mph × 1.609344 = 96.56 km/h.
One mile is defined as exactly 1,609.344 meters, so one mile per hour is exactly 1.609344 kilometers per hour. To convert a speed in mph to km/h you simply multiply by that factor:
km/h = mph × 1.609344
1 mph = 1.609344 km/h · 1 km/h = 0.6213711922 mph
Example. To convert a 70 mph motorway limit to km/h, multiply by 1.609344: 70 mph = 70 × 1.609344 = 112.65 km/h. Going the other way, 100 km/h is 100 × 0.6213711922 = 62.14 mph.
When you need to convert miles per hour to kilometers per hour
Mph-to-km/h conversion comes up whenever a speed given in imperial units has to be read on the metric side. Common cases:
- Driving abroad in a metric country and reading km/h signs after learning to drive in mph.
- Setting a car or motorbike speedometer or head-up display to the local km/h units.
- Comparing US or UK vehicle test figures and top speeds, quoted in mph, against metric specs.
- Translating wind speeds from a US weather forecast into the km/h used elsewhere.
- Logging running, cycling or boat speeds from an mph device into a metric training app.
Frequently asked questions
How many km/h is 1 mph?
One mile per hour equals 1.609344 km/h exactly - a little over one and a half kilometers per hour.
How do I convert mph to km/h?
Multiply the number of miles per hour by 1.609344. For example, 60 mph = 60 × 1.609344 = 96.56 km/h.
What is 70 mph in km/h?
70 mph equals 112.65 km/h (112.65408 km/h to be exact). That is a common motorway and interstate speed limit.
What is a 30 mph speed limit in km/h?
A 30 mph limit is 48.28 km/h, which most countries post as a rounded 50 km/h urban speed limit.
Is mph faster than km/h?
For the same number, yes. Because one mile is longer than one kilometer, 100 mph (160.93 km/h) is faster than 100 km/h (62.14 mph).
How do I convert mph to km/h in my head?
Add about 60 percent to the mph value. For example, 50 mph is roughly 50 + 30 = 80 km/h, and the exact value is 80.47 km/h.
What is 100 mph in km/h?
100 mph equals 160.93 km/h (160.9344 km/h to be exact).
What is 50 km/h in mph?
50 km/h equals 31.07 mph. To convert km/h to mph, multiply by 0.6213711922.
Popular speed unit conversions
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Convert miles per hour to other speed units
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