Velocity
Convert between metric, imperial, and nautical speed units instantly.
Result
0.621372Mile/hour
1 Kilometre/hour in all units
Conversions are calculated using standard velocity unit definitions.
A speed converter transforms measurements of velocity from one unit system to another. Speed describes how fast something moves—distance traveled per unit of time. Common units include kilometers per hour (km/h) used in most countries, miles per hour (mph) standard in the US and UK, meters per second (m/s) used in physics, and knots (nautical miles per hour) used in aviation and maritime navigation.
The converter applies fixed conversion factors between units. Each speed unit has a defined relationship to a base unit (typically meters per second). To convert from one unit to another, the tool divides the input value by that unit's conversion factor, then multiplies by the target unit's conversion factor. For example, 1 km/h equals approximately 0.278 m/s, and 1 mph equals approximately 0.447 m/s. All conversions happen instantly as you enter a value.
| Input | Result | Notes |
|---|---|---|
| 100 km/h | 62.14 mph, 27.78 m/s, 53.99 knots | Common highway speed in Europe; equivalent to typical interstate speed in the US |
| 30 mph | 48.28 km/h, 13.41 m/s, 26.07 knots | Typical residential speed limit; used to check driving safety zones |
| 15 knots | 27.78 km/h, 17.25 mph, 7.72 m/s | Average sailboat speed; essential for maritime navigation planning |
Miles per hour (mph) measures distance in statute miles; kilometers per hour (km/h) uses metric kilometers. 1 mile = 1.609 kilometers, so 60 mph = 96.54 km/h. Most countries outside the US, UK, and a few others use km/h as the standard.
Knots (nautical miles per hour) directly relate to latitude and longitude on charts. A nautical mile is 1 minute of arc on Earth, making navigation calculations simpler. 1 knot = 1.151 mph = 1.852 km/h.
Meters per second (m/s) is the SI unit for velocity, standard in physics and engineering. Use it when calculating kinetic energy, acceleration, or momentum. 10 m/s = 36 km/h = 22.37 mph.
On a highway, 100 km/h (62 mph) is moderate to brisk, depending on local speed limits. In many European countries, 100 km/h is typical motorway traffic. On residential roads, it would be considered dangerously fast.
The converter uses standard NIST conversion factors, accurate to at least 4 decimal places. For everyday purposes like travel and cooking, this precision is more than sufficient.