Instant accurate conversion between all units
| Unit | Value |
|---|
| km/h | mph | m/s | Knots | Common Context |
|---|---|---|---|---|
| 30 | 18.6 | 8.3 | 16.2 | City speed limit |
| 50 | 31.1 | 13.9 | 27.0 | Suburban roads |
| 80 | 49.7 | 22.2 | 43.2 | Rural roads |
| 100 | 62.1 | 27.8 | 54.0 | Highway (metric) |
| 110 | 68.4 | 30.6 | 59.4 | Highway (Australia) |
| 120 | 74.6 | 33.3 | 64.8 | German Autobahn |
| 299,792 | 186,282 | 299,792 | 161,875 | Speed of light |
Multiply mph by 1.60934 to get km/h. Quick mental math: multiply by 1.6. So 60 mph = 96.6 km/h. The US and UK use mph; most countries use km/h.
Knots are used in aviation and maritime navigation. One knot = 1.852 km/h = 1.151 mph. Aircraft speeds, wind speeds in meteorology, and ship speeds are always given in knots.
Multiply m/s by 3.6 to get km/h. So 10 m/s = 36 km/h. Used in physics, science, and for measuring wind speed precisely.
Related: unit converter, length converter, metric vs imperial guide.
Multiply mph by 1.60934. Quick estimate: multiply by 1.6. 60 mph × 1.6 = 96 km/h.
Knots are nautical miles per hour, used in aviation and maritime navigation. 1 knot = 1.852 km/h = 1.151 mph.
Multiply m/s by 3.6. Example: 10 m/s × 3.6 = 36 km/h.
| Speed | km/h | mph | Context |
|---|---|---|---|
| Walking | 5 | 3.1 | Average human walking pace |
| Cycling | 20 | 12.4 | Casual cycling speed |
| City driving | 50 | 31 | Urban speed limit |
| Highway | 100–120 | 62–75 | Standard highway limit |
| Commercial jet | 900 | 559 | Cruising altitude speed |
| Sound | 1,235 | 767 | At sea level, 20°C |
Related: Unit Converter · Metric vs Imperial Guide
km/h (kilometers per hour) is the standard unit worldwide for road speed limits. mph (miles per hour) is used in the US, UK, and a few other countries. Knots are used exclusively in aviation and maritime navigation — 1 knot = 1 nautical mile per hour. m/s (meters per second) is the scientific unit for speed, used in physics and engineering.
Key conversions to memorize: 1 mph = 1.609 km/h. 100 km/h = 62.1 mph. 1 knot = 1.852 km/h. For all other conversions, use the speed converter above. Also see our unit converter for length, weight, and temperature conversions.