Convert speed, instantly.
Meters per second, kilometers per hour, miles per hour, knots and feet per second, side by side.
Speed Converter
Speed conversion benchmarks
🚀 Speed
| 1 mph | 1.60934 km/h |
| 1 knot | 1.852 km/h |
| 1 m/s | 3.6 km/h |
| 100 km/h | 62.14 mph |
How this conversion works
Speed conversions here run through meters per second as the base unit. Knots are used mainly in aviation and maritime navigation and are defined against the nautical mile (1.852 km), which is why the knot-to-km/h factor doesn't line up neatly with the mph one.
For everyday use, the mph ↔ km/h conversion is the one most people reach for: multiply km/h by 0.621371 to get mph, or multiply mph by 1.60934 to get km/h.
Frequently asked questions
Why is a knot different from mph?
A knot is one nautical mile per hour, and a nautical mile (1,852 m) is a different length from a statute mile (1,609.344 m) used in mph. The two units evolved from different measurement traditions — nautical mile from the Earth's circumference, statute mile from Roman/English land surveying.
What's a typical highway speed in km/h vs mph?
A common highway limit of 65 mph is about 105 km/h, and a common European motorway limit of 120 km/h is about 75 mph — useful as a rough mental benchmark when switching between the two.