Speed converter
Miles per Hour to Kilometers per Hour
Miles per Hour and Kilometers per Hour measure the same quantity in different unit systems. The relationship is 1 mph = 1.609344 km/h, which gives 1.609344 km/h per mph. Below you can convert any value, check a worked example and read the full chart.
Formula 1 mph = 1.609344 km/h
Need the other direction? Kilometers per Hour to Miles per Hour.
How to convert Miles per Hour to Kilometers per Hour
Miles per hour is the standard road-speed unit in the US and UK, equal to 1.609344 km/h. Kilometres per hour is the standard road-speed unit in most of the world.
To convert Miles per Hour to Kilometers per Hour, multiply the value in mph by 1.609344. For example, 10 mph × 1.609344 = 16.09344 km/h. This works because the ratio between the two units is constant for every value in speed.
Worked examples
| mph | km/h |
|---|---|
| 1 mph | 1.609344 km/h |
| 2.5 mph | 4.02336 km/h |
| 5 mph | 8.04672 km/h |
| 10 mph | 16.09344 km/h |
| 25 mph | 40.2336 km/h |
| 50 mph | 80.4672 km/h |
| 100 mph | 160.9344 km/h |
Reverse conversion
| km/h | mph |
|---|---|
| 1 km/h | 0.62137119 mph |
| 5 km/h | 3.106856 mph |
| 10 km/h | 6.213712 mph |
| 25 km/h | 15.53428 mph |
| 50 km/h | 31.06856 mph |
| 100 km/h | 62.137119 mph |
When this conversion is useful
This is the calculation you need when you are reading a car spec, a weather report or an aviation document from another country. Because the factor is fixed, you can use the same number for a single measurement or for a batch: 1,000 mph is 1,609.34 km/h.
Is the conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Reference: BIPM SI Brochure and NIST SP 811. Last reviewed: 2026-11-01.
mph to km/h conversion chart
The chart lists the most requested values. For a value that is not here, use the converter at the top of the page.
| Miles per Hour (mph) | Kilometers per Hour (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 |
| 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 | 16.09344 km/h |
| 11 mph | 17.702784 km/h |
| 12 mph | 19.312128 km/h |
| 13 mph | 20.921472 km/h |
| 14 mph | 22.530816 km/h |
| 15 mph | 24.14016 km/h |
| 16 mph | 25.749504 km/h |
| 17 mph | 27.358848 km/h |
| 18 mph | 28.968192 km/h |
| 19 mph | 30.577536 km/h |
| 20 mph | 32.18688 km/h |
| 21 mph | 33.796224 km/h |
| 22 mph | 35.405568 km/h |
| 23 mph | 37.014912 km/h |
| 24 mph | 38.624256 km/h |
| 25 mph | 40.2336 km/h |
| 26 mph | 41.842944 km/h |
| 27 mph | 43.452288 km/h |
| 28 mph | 45.061632 km/h |
| 29 mph | 46.670976 km/h |
| 30 mph | 48.28032 km/h |
| 31 mph | 49.889664 km/h |
| 32 mph | 51.499008 km/h |
| 33 mph | 53.108352 km/h |
| 34 mph | 54.717696 km/h |
| 35 mph | 56.32704 km/h |
| 36 mph | 57.936384 km/h |
| 37 mph | 59.545728 km/h |
| 38 mph | 61.155072 km/h |
| 39 mph | 62.764416 km/h |
| 40 mph | 64.37376 km/h |
| 41 mph | 65.983104 km/h |
| 42 mph | 67.592448 km/h |
| 43 mph | 69.201792 km/h |
| 44 mph | 70.811136 km/h |
| 45 mph | 72.42048 km/h |
| 46 mph | 74.029824 km/h |
| 47 mph | 75.639168 km/h |
| 48 mph | 77.248512 km/h |
| 49 mph | 78.857856 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 |
| 90 mph | 144.84096 km/h |
| 100 mph | 160.9344 km/h |
Frequently asked questions
How many Kilometers per Hour are in 1 Miles per Hour?
1 mph equals 1.609344 km/h.
How do I convert Miles per Hour to Kilometers per Hour?
Multiply the mph value by 1.609344. Example: 25 mph = 40.2336 km/h.
What is 2.5 mph in km/h?
2.5 mph = 4.02336 km/h.
Is the mph to km/h conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Does the calculator work offline?
Yes. The conversion runs in your browser with JavaScript, so it works after the page has loaded, even without a connection.