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Instantly convert speed between miles per hour (mph), kilometers per hour (km/h), knots, and meters per second (m/s). Free automotive and aerospace calculator.
Visual speed comparison like a car dashboard
| Miles per hour (mph) | Kilometers per hour (km/h) | Kilometers per hour (Reverse) | Miles per hour Equivalent | Action |
|---|---|---|---|---|
| 0.1 mph | 0.16093 km/h | 0.1 km/h | 0.06214 mph | |
| 0.5 mph | 0.80467 km/h | 0.5 km/h | 0.31069 mph | |
| 1 mph | 1.60934 km/h | 1 km/h | 0.62137 mph | |
| 2 mph | 3.21869 km/h | 2 km/h | 1.24274 mph | |
| 5 mph | 8.04672 km/h | 5 km/h | 3.10686 mph | |
| 10 mph | 16.09344 km/h | 10 km/h | 6.21371 mph | |
| 20 mph | 32.18688 km/h | 20 km/h | 12.42742 mph | |
| 50 mph | 80.46720 km/h | 50 km/h | 31.06856 mph | |
| 100 mph | 160.93440 km/h | 100 km/h | 62.13712 mph | |
| 500 mph | 804.67200 km/h | 500 km/h | 310.68560 mph | |
| 1000 mph | 1,609.34400 km/h | 1000 km/h | 621.37119 mph |
Symbol: m/s. Commonly used in: metric.
Symbol: km/h. Commonly used in: metric.
Symbol: mph. Commonly used in: imperial.
Symbol: kn. Commonly used in: other.
Symbol: ft/s. Commonly used in: imperial.
Every conversion starts with the standard baseline rate between these two units:
Multiply your entered number by the conversion rate to calculate the exact target value:
The result is neatly rounded to your preferred decimal setting so it is clear and ready to use:
| Unit Name | Symbol | System | Conversion Rate | Common Uses |
|---|---|---|---|---|
| Meters per second | m/s | metric | 1 m/s = 1.000000 m/s | Everyday, home, and school measurements in Speed & Velocity. |
| Kilometers per hour | km/h | metric | 1 km/h = 0.277778 m/s | Everyday, home, and school measurements in Speed & Velocity. |
| Miles per hour | mph | imperial | 1 mph = 0.447040 m/s | Everyday, home, and school measurements in Speed & Velocity. |
| Knot (Nautical mi/h) | kn | other | 1 kn = 0.514444 m/s | Everyday, home, and school measurements in Speed & Velocity. |
| Feet per second | ft/s | imperial | 1 ft/s = 0.304800 m/s | Everyday, home, and school measurements in Speed & Velocity. |
| Mach (at sea level, 20°C) | Ma | other | 1 Ma = 343.000000 m/s | Everyday, home, and school measurements in Speed & Velocity. |
| Speed of Light in Vacuum | c | si | 1 c = 299,792,458.000000 m/s | Everyday, home, and school measurements in Speed & Velocity. |
The knot originated in the 16th century, where sailors threw a wooden log attached to a knotted rope behind the ship and counted how many knots passed in 30 seconds as timed by an hourglass.
Do not confuse speed (scalar magnitude) with velocity (vector containing magnitude and direction).
Multiply km/h by 0.62. Or multiply by 6 and divide by 10. For example: 80 km/h × 0.62 = 49.6 mph (exact: 49.71 mph).
A knot is one nautical mile per hour (1.852 km/h or approximately 1.151 mph).
Every calculation uses trusted, standard definitions so your results are 100% accurate for school, home, work, and recipes.
