MPH to KPH Converter
Convert miles per hour (mph) to kilometers per hour (kph, also written km/h) in one step, with the formula, speed-limit examples and a quick-reference table.
KPH = MPH × 1.609344
MPH to KPH Formula
One mile is exactly 1.609344 kilometers, so to convert mph to kph you multiply by 1.609344. To convert kph to mph, divide by 1.609344. The same factor works for any speed expressed per hour.
About MPH and KPH
Miles per hour (mph) is the speed unit on road signs in the United States and the United Kingdom. Kilometers per hour (kph or km/h) is used in most other countries. Both measure distance covered in one hour, and the conversion depends only on the mile being exactly 1.609344 kilometers.
How to Convert MPH to KPH
- Enter the speed in miles per hour. Decimals such as 37.5 are fine.
- The answer in kilometers per hour appears instantly, or press Convert Now.
- Use Swap Units to convert kph to mph, Copy Result to copy the answer, or Clear to start again.
By hand: multiply the mph by 1.609344. A quick mental rule is to multiply by 1.6, or add half and then a tenth: 50 mph is about 50 + 25 + 5 = 80 km/h (exact: 80.4672). Speed here is the magnitude of velocity, so only zero and positive values are accepted.
Practical Examples
- Urban speed limit: 30 mph = 48.28032 km/h.
- Highway limit: 65 mph = 104.60736 km/h, and 70 mph = 112.65408 km/h.
- School zone: 20 mph = 32.18688 km/h.
- Fastball: a 95 mph pitch is 152.88768 km/h.
- Sprinter: 23 mph is 37.014912 km/h.
MPH to KPH – Common Values
Quick reference for frequently used conversions
| Miles per hour (mph) | Kilometers per hour (km/h) | Meters per second (m/s) |
|---|---|---|
| 5 mph | 8.04672 km/h | 2.2352 m/s |
| 10 mph | 16.09344 km/h | 4.4704 m/s |
| 15 mph | 24.14016 km/h | 6.7056 m/s |
| 20 mph | 32.18688 km/h | 8.9408 m/s |
| 25 mph | 40.2336 km/h | 11.176 m/s |
| 30 mph | 48.28032 km/h | 13.4112 m/s |
| 35 mph | 56.32704 km/h | 15.6464 m/s |
| 40 mph | 64.37376 km/h | 17.8816 m/s |
| 45 mph | 72.42048 km/h | 20.1168 m/s |
| 50 mph | 80.4672 km/h | 22.352 m/s |
| 55 mph | 88.51392 km/h | 24.5872 m/s |
| 60 mph | 96.56064 km/h | 26.8224 m/s |
| 65 mph | 104.60736 km/h | 29.0576 m/s |
| 70 mph | 112.65408 km/h | 31.2928 m/s |
| 75 mph | 120.7008 km/h | 33.528 m/s |
| 80 mph | 128.74752 km/h | 35.7632 m/s |
| 100 mph | 160.9344 km/h | 44.704 m/s |
Where and Why This Conversion Is Used
The United States and the United Kingdom use miles per hour on road signs, while most of the world uses kilometers per hour. Switching between them is a daily need for drivers, travellers and fans of motor sport.
- Driving abroad: speed limits, car speedometers and rental cars may use the other unit.
- Vehicles and imports: top speeds and specifications in car reviews often appear in both.
- Sport: pitch, serve and sprint speeds are quoted in mph in the US and km/h elsewhere.
- Weather: wind speeds and storm categories can be reported in either unit.
- Aviation and marine: ground speed is often converted between mph, km/h and knots.
For distances see the KM to Miles Converter.