Speed Converter
Convert between mph, kph, m/s, knots, and fps.
Speed Reference
| From | To | Value |
|---|---|---|
| 1 mph | kph | 1.60934 kph |
| 1 m/s | kph | 3.6 kph |
| 1 knot | mph | 1.15078 mph |
| 100 kph | mph | 62.1371 mph |
| Speed of sound | m/s | 343 m/s |
Speed is measured differently depending on context and location. Miles per hour (mph) is standard in the United States and United Kingdom for road speeds. Kilometers per hour (km/h) is used in most other countries. Meters per second (m/s) is the SI unit used in science and physics. Knots are used in aviation and maritime navigation. This free speed converter handles all of these units instantly.
How to use this tool
- Enter the speed value you want to convert.
- Select the unit you are converting from (e.g. mph or km/h).
- Select the target unit. The converted speed is shown immediately.
Frequently asked questions
How do I convert mph to km/h?
Multiply the mph value by 1.60934 to get km/h. For example, 60 mph × 1.60934 = 96.56 km/h. Our converter does this automatically.
What is a knot in mph?
One knot equals 1.15078 miles per hour, or 1.852 km/h. Knots are used by ships and aircraft to measure speed relative to the water or air.
How fast is the speed of sound?
The speed of sound in dry air at sea level is approximately 343 meters per second (767 mph or 1,235 km/h). This varies with temperature and altitude.
What is Mach 1?
Mach 1 is the speed of sound — approximately 343 m/s, 767 mph, or 1,235 km/h at sea level. Mach 2 would be twice the speed of sound.