Speed Converter
Convert between km/h, mph, m/s, knots and more instantly
| Amount | Mile/Hour |
|---|---|
| 1 km/h | 0.62137119 mph |
| 2 km/h | 1.2427424 mph |
| 5 km/h | 3.106856 mph |
| 10 km/h | 6.2137119 mph |
| 25 km/h | 15.53428 mph |
| 50 km/h | 31.06856 mph |
| 100 km/h | 62.137119 mph |
| 500 km/h | 310.6856 mph |
| 1,000 km/h | 621.37119 mph |
Speed Converter: km/h, mph, m/s, Knots & More
This free speed converter changes a speed from one unit to another, instantly and accurately. Convert kilometers per hour, miles per hour, meters per second, knots, feet per second, centimeters per second, kilometers per second and more, up to Mach and the speed of light. Pick your units, type a speed or move the slider, and you also get the formula, everyday reference speeds and a comparison table.
Quick answer: 100 km/h is 62.14 mph, 60 mph is 96.56 km/h, and 1 m/s is 3.6 km/h. So a 120 km/h limit is about 74.6 mph, and 65 mph is about 104.6 km/h.
How to Convert Speed
Speed conversion multiplies by a fixed factor. To change km/h to mph, multiply by 0.621371, and to change mph to km/h, multiply by 1.609344. The converter first changes your value to meters per second and then into the unit you chose, so every pair of units works, including knots to feet per second.
| From | To | Multiply by |
|---|---|---|
| km/h | mph | 0.621371 |
| mph | km/h | 1.609344 |
| m/s | km/h | 3.6 |
| km/h | m/s | 0.277778 |
| knots | km/h | 1.852 |
| knots | mph | 1.150779 |
| m/s | mph | 2.236936 |
| ft/s | mph | 0.681818 |
Example: 100 km/h × 0.621371 = 62.14 mph, and 20 m/s × 3.6 = 72 km/h.
Kilometers per Hour and Miles per Hour
Road signs, speedometers and car specifications use km/h in most of the world and mph in the United States and the UK. These values use the exact definitions, so they match the converter above:
| km/h | mph | m/s |
|---|---|---|
| 5 km/h | 3.11 mph | 1.39 m/s |
| 10 km/h | 6.21 mph | 2.78 m/s |
| 30 km/h | 18.64 mph | 8.33 m/s |
| 50 km/h | 31.07 mph | 13.89 m/s |
| 80 km/h | 49.71 mph | 22.22 m/s |
| 100 km/h | 62.14 mph | 27.78 m/s |
| 120 km/h | 74.56 mph | 33.33 m/s |
| 300 km/h | 186.41 mph | 83.33 m/s |
| mph | km/h | knots |
|---|---|---|
| 5 mph | 8.05 km/h | 4.34 kn |
| 20 mph | 32.19 km/h | 17.38 kn |
| 30 mph | 48.28 km/h | 26.07 kn |
| 40 mph | 64.37 km/h | 34.76 kn |
| 55 mph | 88.51 km/h | 47.79 kn |
| 60 mph | 96.56 km/h | 52.14 kn |
| 65 mph | 104.61 km/h | 56.48 kn |
| 70 mph | 112.65 km/h | 60.83 kn |
| 75 mph | 120.7 km/h | 65.17 kn |
Knots, Meters per Second and Mach
Ships and aircraft use knots, where one knot is one nautical mile per hour, or exactly 1.852 km/h. Science and engineering use meters per second, the SI unit. Mach compares a speed to the speed of sound, which changes with temperature and altitude, so this converter uses the standard sea-level value of 340.29 m/s. Runners can compare their pace with the pace calculator, and the distance and time behind a trip can be found with the time converter and the length converter.
Everyday Speeds for Comparison
It helps to picture a speed. A brisk walk is about 5 km/h, a bicycle about 20 km/h, a car on a motorway around 100 to 120 km/h, and a jet airliner about 900 km/h. The reference and comparison panels in the tool list these and more, and tapping one fills the converter.
| Speed | km/h | mph |
|---|---|---|
| Walking pace | 5 | 3.11 |
| Cycling | 20 | 12.43 |
| City speed limit | 50 | 31.07 |
| Highway | 100 | 62.14 |
| High-speed train | 300 | 186.41 |
| Airliner cruise | 900 | 559.23 |
| Speed of sound (sea level) | 1,225.04 | 761.21 |
Who Uses a Speed Converter?
Drivers and travelers use it to understand speed limits abroad, and runners and cyclists use it to compare pace and speed. Sailors and pilots use it to move between knots and km/h, and students and engineers use it for physics and design work. Anyone reading a vehicle specification or a weather report in another unit can use it for a quick answer. For other measurements, see the unit converter, which brings every category together.
How to Use This Speed Converter
Enter the speed
Type a number, move the slider, or tap a quick speed like walking pace or the highway.
Choose your units
Pick the starting unit and the target unit, or use the Km/h, Mph and M/s shortcuts and the swap button.
Read the result
The answer appears instantly, along with the speed in m/s, km/h, mph and knots.
Explore the extras
Open Formula, Reference, Comparison or Difference to see the factor, everyday speeds or the gap between two speeds.