Kilometers per Hour vs Miles per Hour
Compare kilometers per hour and miles per hour side by side, convert in both directions, and see the exact factor - Speed units.
= 0.621371 mph
= 1.6093 km/h
1 kilometer per hour = 0.621371 mph · 1 mile per hour = 1.6093 km/h
The Kilometers per Hour is the smaller unit - the same amount has a smaller number when measured in it.
| Kilometers per Hour (km/h) | Miles per Hour (mph) | Miles per Hour (mph) | Kilometers per Hour (km/h) |
|---|---|---|---|
| 1 | 0.621371 | 1 | 1.6093 |
| 2 | 1.2427 | 2 | 3.2187 |
| 5 | 3.1069 | 5 | 8.0467 |
| 10 | 6.2137 | 10 | 16.0934 |
| 25 | 15.5343 | 25 | 40.2336 |
| 50 | 31.0686 | 50 | 80.4672 |
| 100 | 62.1371 | 100 | 160.9 |
| 250 | 155.3 | 250 | 402.3 |
| 500 | 310.7 | 500 | 804.7 |
| 1000 | 621.4 | 1000 | 1,609 |
Quick Answer
1 kilometer per hour (km/h) = 0.621371 miles per hour (mph), and 1 mile per hour = 1.6093 kilometers per hour. Miles per Hour is the larger unit, so the same physical amount needs a bigger number when measured in kilometers per hour. Convert either way with the live tool below or the dedicated converter pages.
Key Facts
- 1 kilometer per hour (km/h) = 0.621371 mph
- 1 mile per hour (mph) = 1.6093 km/h
- Conversion is exact multiplication - no rounding in the factor
- Table below covers common values in both directions
- Dedicated converters: km/h→mph and mph→km/h pages with live tools
Frequently Asked Questions
Which is bigger, a kilometer per hour or a mile per hour?
One kilometer per hour equals 0.621371 mph, and one mile per hour equals 1.6093 km/h. The unit with the larger factor is the physically bigger one.
How do I convert kilometers per hour to miles per hour?
Multiply by the factor: value in mph = value in km/h × 0.621371. Example: 5 km/h = 3.1069 mph. Reverse: divide by 0.621371 (or multiply by 1.6093).
Why are kilometers per hour and miles per hour different?
They come from different measurement systems - Kilometers per Hour belongs to the metric (SI) world, Miles per Hour to the US customary world (or another convention). The conversion is exact: 0.621371 mph per kilometer per hour, no rounding needed for the factor itself.
Is there a quick way to convert without a calculator?
Memorize the 1-to factor: 1 kilometer per hour ≈ 0.621371 mph. Then multiply. For 2 km/h that's ≈ 1.2427 mph.
Frequently Asked Questions
One kilometer per hour equals 0.621371 mph, and one mile per hour equals 1.6093 km/h. The unit with the larger factor is the physically bigger one.
Multiply by the factor: value in mph = value in km/h × 0.621371. Example: 5 km/h = 3.1069 mph. Reverse: divide by 0.621371 (or multiply by 1.6093).
They come from different measurement systems - Kilometers per Hour belongs to the metric (SI) world, Miles per Hour to the US customary world (or another convention). The conversion is exact: 0.621371 mph per kilometer per hour, no rounding needed for the factor itself.
Memorize the 1-to factor: 1 kilometer per hour ≈ 0.621371 mph. Then multiply. For 2 km/h that's ≈ 1.2427 mph.