Convert kilometers per hour to miles per hour
Converting kilometers per hour to miles per hour is a common speed task, whether you are checking a recipe, a spec sheet, a travel distance or a homework problem. Since 1 km/h equals 0.621371 mph, the math is a single multiplication — and this page does it for you instantly, with the formula, a table of common values and answers to the questions people ask most.
Exact factor
How to convert kilometers per hour to miles per hour
To convert kilometers per hour to miles per hour, multiply the number of kilometers per hour by 0.621371. For example, 10 km/h × 0.621371 = 6.21371 mph.
mph = km/h × 0.621371
- Write down the value in kilometers per hour you want to convert.
- Multiply it by 0.621371 (the exact km/h→mph factor).
- The result is your value in miles per hour. Check it below with the converter or the table.
Conversion table
Common values of kilometers per hour and their equivalents in miles per hour:
| km/h | mph |
|---|---|
| 1 | 0.621371 |
| 2 | 1.24274 |
| 3 | 1.86411 |
| 4 | 2.48548 |
| 5 | 3.10686 |
| 10 | 6.21371 |
| 20 | 12.4274 |
| 25 | 15.5343 |
| 50 | 31.0686 |
| 100 | 62.1371 |
| 250 | 155.343 |
| 500 | 310.686 |
About these units
Kilometer per Hour (km/h). Kilometers per hour is the standard speed unit for road traffic in metric countries, expressing how many kilometers are covered in one hour. Speed limits and car speedometers use km/h.
Mile per Hour (mph). Miles per hour is the road speed unit in the United States and the United Kingdom, expressing how many statute miles are covered in one hour. One mph equals exactly 0.44704 m/s.
Frequently asked questions
How do I convert kilometers per hour to miles per hour?
To convert kilometers per hour to miles per hour, multiply the number of kilometers per hour by 0.621371. For example, 10 km/h × 0.621371 = 6.21371 mph. Or skip the math: type the value into the converter at the top of this page and the result updates instantly.
How many miles per hour are in 1 kilometer per hour?
1 km/h = 0.621371 mph. That is the fixed relationship used by this converter and by international standards.
How many kilometers per hour are in 1 mile per hour?
1 mph = 1.60934 km/h. If you are converting in the opposite direction, use our Mile per Hour to Kilometer per Hour converter for the dedicated table and FAQ.
Is the kilometers per hour to miles per hour conversion exact?
Yes. Both units are defined by international agreement, so the factor of 0.621371 is exact. Displayed results are rounded to 6 significant digits only for readability.
What is kilometer per hour used for?
Kilometers per hour is the standard speed unit for road traffic in metric countries, expressing how many kilometers are covered in one hour. Speed limits and car speedometers use km/h.