How to convert miles per hour to kilometers per hour
To convert miles per hour to kilometers per hour, multiply by 1.609344. One mile per hour is exactly 1.609344 km/h, a conversion travelers need when driving abroad or comparing car and treadmill speeds.
Mile per Hour to Kilometer per Hour conversion table
| Mile per Hour (mph) | Kilometer per Hour (km/h) |
|---|---|
| 0.1 mph | 0.1609344 km/h |
| 0.5 mph | 0.804672 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 | 8.04672 km/h |
| 10 mph | 16.09344 km/h |
| 20 mph | 32.18688 km/h |
| 25 mph | 40.2336 km/h |
| 50 mph | 80.4672 km/h |
| 100 mph | 160.9344 km/h |
| 500 mph | 804.672 km/h |
| 1,000 mph | 1,609.344 km/h |
About the units
Mile per Hour (mph)
Miles per hour is the road speed unit in the US and UK; 1 mph is exactly 0.44704 m/s.
Kilometer per Hour (km/h)
Kilometers per hour is the road speed unit used in most of the world.
How to use this converter
- Type the number of miles per hour (mph) in the input box.
- The result in kilometers per hour appears instantly — no button needed.
- See the same value in every other speed unit just below.
- Use “Swap units” to convert kilometers per hour back to miles per hour.
When you’ll use the mile per hour to kilometer per hour conversion
You are driving a rental car in Ireland and your phone’s map app shows a speed limit of 50 mph from home settings. Converting gives about 80 km/h, matching the road signs you will actually see.
A US running plan says to run intervals at 7 mph, but the hotel treadmill shows km/h. Converting gives about 11.3 km/h.
💡 For a quick estimate in your head, multiply by about 1.6 (the exact factor is 1.609344).
Watch out for these mix-ups
- Multiplying by 1.6 for precise speeds such as wind measurements.
- Assuming UK road signs use km/h — they use mph.
- Mixing up the direction of conversion.
- Comparing wind speeds in knots with speeds in mph.
Tips for better results
- Multiply mph by 1.609 for km/h.
- Remember 60 mph is about 97 km/h.
- Use the speed converter if knots or m/s are involved.
💡 Practical tip: A quick estimate: add 60% to the mph figure — 50 mph becomes about 80 km/h.
Frequently asked questions
How many kilometers per hour are in one mile per hour?
One mile per hour equals 1.609344 kilometers per hour. 1.609344 is the exact factor used by this converter.
How do I convert miles per hour to kilometers per hour?
Multiply the value in miles per hour by 1.609344. To go the other way, multiply kilometers per hour by 0.621371192237.
What is 10 mph in km/h?
10 mph = 16.09344 km/h. Also, 5 mph = 8.04672 km/h and 100 mph = 160.9344 km/h.
What is the difference between a mile per hour and a kilometer per hour?
Miles per hour is the road speed unit in the US and UK; 1 mph is exactly 0.44704 m/s. Kilometers per hour is the road speed unit used in most of the world.
Is this tool free and private?
Yes — the Mile per Hour to Kilometer per Hour is completely free with no sign-up, and it runs entirely in your browser, so the values you enter are never uploaded to our servers.
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