Kilometers Per Hour to Miles Per Hour
Kilometers per hour is the standard speed unit on road signs and speedometers outside the US and UK. Miles per hour is the standard speed unit on road signs and speedometers in the US and UK. 1 km/h equals ≈0.621371 mph, so converting between them is a matter of multiplying by that fixed factor — type any value into the converter below and both sides update instantly as you type.
Both units belong to speed, measured here against speed's base unit (m/s) — every other speed unit on this site converts through that same reference point, which is why the table below can also be read as a quick cross-check against nearby values.
Formula
mph = km/h × ≈0.621371
km/h = mph × ≈1.60934
Worked example: 5 km/h × ≈0.621371 = ≈3.10686 mph.
Conversion table
| Kilometer per hour (km/h) | Mile per hour (mph) |
|---|---|
| 1 km/h | ≈0.621371 mph |
| 2 km/h | ≈1.24274 mph |
| 3 km/h | ≈1.86411 mph |
| 5 km/h | ≈3.10686 mph |
| 10 km/h | ≈6.21371 mph |
| 20 km/h | ≈12.4274 mph |
| 25 km/h | ≈15.5343 mph |
| 50 km/h | ≈31.0686 mph |
| 100 km/h | ≈62.1371 mph |
| 250 km/h | ≈155.343 mph |
| 500 km/h | ≈310.686 mph |
| 1,000 km/h | ≈621.371 mph |
Frequently asked
- How many Miles per hour in a kilometer per hour?
- 1 km/h equals ≈0.621371 mph.
- How do I convert Kilometers per hour to Miles per hour?
- Multiply the value in km/h by ≈0.621371 to get mph. The converter above does this instantly as you type.
- Is the conversion exact?
- Yes — Kilometer per hour and Mile per hour are both defined by a fixed conversion factor to speed's base unit (m/s), so the result shown is exact to the precision displayed, not an approximation.