Speed
km/h, mph, knots, m/s
About This Calculator
Speed measures distance traveled per unit of time. Miles per hour is standard in the US and UK, kilometers per hour in most other countries, knots in aviation and maritime contexts, and meters per second in scientific work.
Formula
1 mph = 1.60934 km/h = 0.44704 m/s
1 knot = 1.852 km/h = 1.15078 mph
1 m/s = 3.6 km/h = 2.23694 mph
Example Calculation
Convert 60 mph to km/h and m/s.
- km/h = 60 × 1.60934 = 96.56 km/h
- m/s = 60 × 0.44704 = 26.82 m/s
60 mph = 96.56 km/h = 26.82 m/s
Common Speeds Reference
| Activity | mph | km/h | m/s |
|---|---|---|---|
| Walking | 3 | 4.8 | 1.3 |
| Running | 9 | 14.5 | 4.0 |
| Highway driving | 65 | 104.6 | 29.1 |
| Speed of sound | 767 | 1235 | 343 |
Frequently Asked Questions
How do I convert km/h to mph?
Multiply by 0.621371. For example, 100 km/h = 100 × 0.621371 = 62.1 mph. To convert mph to km/h, multiply by 1.60934.
What is a knot?
A knot is one nautical mile per hour (1.852 km/h). It is used by ships and aircraft because nautical miles align with degrees of latitude, simplifying navigation.
How fast is the speed of light?
The speed of light is approximately 299,792,458 m/s, or about 186,282 miles per second. Nothing with mass can travel at or faster than this speed.