Speed Converter
The speed converter changes values between kilometres per hour, miles per hour, metres per second, knots, feet per second and Mach. It is useful for driving, cycling, aviation, marine navigation and physics problems. Results update live as you type, and the speedometer gives a quick sense of whether the converted speed is walking pace, highway speed or beyond ordinary road travel.
Speedometer
How to Use
- Type the number you want to convert in the Value field at the top.
- Select the unit you are converting from in the left dropdown.
- Select the unit you want to convert to in the right dropdown.
- Read the live result below; there is no calculate button.
- Use the Swap button to reverse the conversion direction instantly.
Speeds of Real-World Things
| Object/Activity | km/h | mph | m/s |
|---|---|---|---|
| Walking pace | 5 | 3.1 | 1.39 |
| Cycling | 20 | 12.4 | 5.56 |
| City speed limit | 50 | 31.1 | 13.9 |
| Highway speed | 100 | 62.1 | 27.8 |
| Cheetah (fastest land) | 120 | 74.6 | 33.3 |
| Commercial airplane | 900 | 559 | 250 |
| Speed of sound | 1235 | 767 | 343 |
| Bullet (rifle) | 1800 | 1118 | 500 |
| Speed of light | 1,079,251,200 | 670,616,629 | 299,792,458 |
FAQ
What is the difference between speed and velocity?
Speed is how fast something moves. Velocity includes both speed and direction.
What does Mach 1 mean and how fast is it?
Mach 1 is the speed of sound. This converter uses 343 m/s, approximately 1235 km/h at sea level near 20°C.
What is a knot and why is it used in aviation?
A knot is one nautical mile per hour. It is used in aviation and marine navigation because distances are often based on nautical miles.
How do you convert km/h to m/s?
Divide kilometres per hour by 3.6 to get metres per second.
What is the speed of sound in air?
At sea level around 20°C, the speed of sound in air is about 343 m/s.