mph to km/h Conversion Calculator
Click on the following link if you want to convert kilometers per hour to miles per hour – km/h to mph
History
The mile per hour (mph) was originally used in England in the 17th century, long before the metric system existed.
It was based on the statute mile, defined as 1,609.34 meters.
The kilometer per hour (km/h) came later with the introduction of the metric system, which is now standard worldwide.
Both are still widely recognized, especially in global travel and automotive industries.
Common Usage
- mph is still used for speed limits and vehicles in the U.S. and U.K.
- km/h is used in almost every other country.
For example, when driving in the U.S. at 60 mph, that’s about 97 km/h in Europe.
Conversion Formula
To convert miles per hour to kilometers per hour:
km/h = mph × 1.609
Example:
Convert 70 mph to km/h.
70 × 1.609 = 112.63 km/h
So, 70 mph is approximately 113 km/h.
Conversion Table
| Miles per Hour (mph) | Kilometers per Hour (km/h) |
|---|---|
| 10 mph | 16.09 km/h |
| 20 mph | 32.19 km/h |
| 30 mph | 48.28 km/h |
| 40 mph | 64.37 km/h |
| 50 mph | 80.47 km/h |
| 60 mph | 96.56 km/h |
| 70 mph | 112.65 km/h |
| 80 mph | 128.75 km/h |
| 90 mph | 144.84 km/h |
| 100 mph | 160.93 km/h |
Interesting Facts
- The speed of sound at sea level is about 767 mph or 1,235 km/h.
- Typical U.S. highway limits are 55–70 mph (90–113 km/h).
- The fastest speeding ticket ever issued in the U.S. was for 242 mph (389 km/h).
Frequently Asked Questions
1. How many kilometers per hour are in one mile per hour?
1.609 km/h.
2. How do I convert mph to km/h?
Multiply by 1.609.
3. Why are mph and km/h both still used?
Because some countries never fully adopted the metric system.
4. Is 60 mph faster than 100 km/h?
No, 60 mph = 96.56 km/h, slightly slower.
5. Which is the official SI unit for speed?
Meters per second (m/s) is the SI base unit, but km/h is used for daily life.
