Convert Miles per hour to Kilometres per hour
1 mile per hour is 1.609344 km/h. One mile per hour is exactly 1.609344 kilometres per hour.
One mile per hour is 1.609344 kilometres per hour. To convert miles per hour to kilometres per hour, multiply by 1.609344; to go the other way, divide by 1.609344 or multiply by 0.62137119. The factor is exact rather than rounded: it follows from NIST Special Publication 811. Exactly 0.44704 m/s, because a mile is exactly 1,609.344 metres.
Factor checked against the defining standard · How we check
- Miles per hour × 1.609344
value * 1.6093441.609 km/h
1 mile per hour in every speed unit
| Unit | Value | Exact factor |
|---|---|---|
| metres per second | 0.44704 m/s | × 0.44704 |
| kilometres per hour | 1.609344 km/h | × 1.609344 |
| miles per hour (as entered) | 1 mph | — |
| knots | 0.8689762419 kn | × 0.868976241901 |
| feet per second | 1.466666667 ft/s | × 1.46666666667 |
Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert miles per hour to kilometres per hour?
- 1.Take the measurement in miles per hour.
- 2.Multiply by 1.609344 — that is how many kilometres per hour fit in one mile per hour.
- 3.To go back the other way, divide by 1.609344, or multiply by 0.62137119.
Miles per hour to kilometres per hour conversion table
| Miles per hour | Kilometres per hour |
|---|---|
| 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 |
| 12 mph | 19.312128 km/h |
| 15 mph | 24.14016 km/h |
| 20 mph | 32.18688 km/h |
| 25 mph | 40.2336 km/h |
| 50 mph | 80.4672 km/h |
| 100 mph | 160.9344 km/h |
What are miles per hour and kilometres per hour?
- Mile per hour (mph)
- Exactly 0.44704 m/s, because a mile is exactly 1,609.344 metres. US and UK road speeds.
- Kilometre per hour (km/h)
- Exactly one kilometre divided by 3,600 seconds. The road speed unit almost everywhere outside the United States and the United Kingdom.
Source: NIST Special Publication 811 — conversion factors for speed
Questions people actually ask
- How many kilometres per hour are in a mile per hour?
- 1.609344. Exactly one kilometre divided by 3,600 seconds. The road speed unit almost everywhere outside the United States and the United Kingdom.
- How do I convert kilometres per hour back to miles per hour?
- Divide by 1.609344, or multiply by 0.62137119 — they are the same operation.
Other speed conversions
Kilometres per hour to miles per hour — the same conversion the other way.