Kilometers per Hour to Miles per Hour Converter
Enter the speed in kilometers per hour below to convert it to miles per hour.
Convert Kilometers per Hour to Miles per Hour
Enter a value in kilometers per hour (km/h) to convert to miles per hour (mph).
Kilometers per Hour to Miles per Hour Conversion Table
Table showing various kilometers per hour measurements converted to miles per hour. Click any preset value or arrow to load it into the converter.
| Kilometers per Hour (km/h) | Miles per Hour (mph) |
|---|---|
| 1 km/h | 0.6213712 mph |
| 2 km/h | 1.2427424 mph |
| 5 km/h | 3.106856 mph |
| 10 km/h | 6.2137119 mph |
| 15 km/h | 9.3205679 mph |
| 20 km/h | 12.4274238 mph |
| 25 km/h | 15.5342798 mph |
| 30 km/h | 18.6411358 mph |
| 50 km/h | 31.0685596 mph |
| 75 km/h | 46.6028394 mph |
How to Convert Kilometers per Hour to Miles per Hour
To convert kilometers per hour to miles per hour, multiply the speed by the following conversion ratio: 0.6213712 miles per hour/kilometers per hour.
Since one kilometers per hour is equal to 0.6213712 miles per hour, you can use this simple formula to convert:
The speed in miles per hour is equal to the speed in kilometers per hour multiplied by 0.6213712.
For example, here's how to convert 100 kilometers per hour to miles per hour using the formula above.
How Many Miles per Hour Are in a Kilometers per Hour?
There are 0.6213712 miles per hour in a kilometers per hour, which is why we use this value in the formula above.
Our kilometers per hour to miles per hour calculator automatically converts your speed measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Kilometers per Hour and miles per hour are both units used to measure speed. Keep reading to learn more about each unit.
What Is a Kilometers per Hour?
A kilometers per hour is a unit of speed equal to 0.2777778 meters per second (m/s), the base unit for speed. Standard metric road speed unit (1 m/s = 3.6 km/h). [1]
The kilometers per hour is classified as a metric and SI-compatible unit of speed. Kilometers per Hour can be abbreviated as km/h; for example, 1 kilometers per hour can be written as 1 km/h.
In the metric system, "kilo" is the standard SI prefix for thousands, or 10³. This makes the kilometers per hour (km/h) a convenient decimal multiple of the meters per second (m/s).
In practice, kilometers per hour (km/h) are widely used across standard speed applications within SI metric workflows, engineering documentation, and technical data sheets.
What Is a Miles per Hour?
A miles per hour is a unit of speed equal to 0.44704 meters per second (m/s), the base unit for speed. Imperial & US road speed unit (1 mph = 1.609344 km/h). [2]
The miles per hour is classified as a US customary and imperial unit of speed. Miles per Hour can be abbreviated as mph; for example, 1 miles per hour can be written as 1 mph.
When working with miles per hour (mph) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, miles per hour (mph) are widely used across standard speed applications within US customary and imperial workflows, engineering documentation, and technical data sheets.
When converting speed between kilometers per hour (km/h) and miles per hour (mph), keep full floating-point precision (1 km/h = 0.6213712 mph; 1 mph = 1.609344 km/h) during intermediate calculations and round only the final miles per hour figure to match your instrument tolerance.
More Kilometers per Hour & Miles per Hour Conversions
Need to calculate in the opposite direction? Use our miles per hour to kilometers per hour converter (mph to km/h) to switch your starting unit immediately. You can also explore related tools such as converting knots to miles per hour, converting feet per second to miles per hour, or converting kilometers per hour to meters per second.
Convert from Kilometers per Hour
Frequently Asked Questions
References
- [1]NIST SP 811 StandardNIST SP 811 (NIST SP 811 App. B.9 (Velocity))·Speed Metrology Standard — Kilometers per Hour (km/h) to Miles per Hour (mph)
- [2]NIST OWM SpecificationNIST OWM (SI Units — Length & Distance)·Unit Specifications: Kilometers per Hour (km/h) & Miles per Hour (mph)
- [3]NIST CUU ReferenceNIST CUU (SI Coherent Derived Units (m/s))·Conversion Factors & Mathematical Basis (km/h to mph)