Speed Converter

Convert between all speed units. Select a conversion from the table below.

Metres per second

Metres per second (m/s) is the SI unit of speed. It measures the distance in metres covered per second of time. It is used in physics and engineering for precise speed measurements and scientific calculations.

1 m/s to km/h 1 m/s to mph 1 m/s to kn 1 m/s to ft/s

Kilometres per hour

Kilometres per hour (km/h) is the most widely used unit of speed for road transportation. Speed limits and vehicle speedometers in most countries display speed in km/h. One km/h equals approximately 0.621 mph.

1 km/h to m/s 1 km/h to mph 1 km/h to kn 1 km/h to ft/s

Miles per hour

Miles per hour (mph) is the standard unit of speed for road transportation in the United States, United Kingdom, and a few other countries. One mph equals approximately 1.609 km/h.

1 mph to m/s 1 mph to km/h 1 mph to kn 1 mph to ft/s

Knot

The knot (kn) is a unit of speed equal to one nautical mile per hour. It is the standard measure of speed in aviation and maritime navigation. One knot equals approximately 1.852 km/h or 1.151 mph.

1 kn to m/s 1 kn to km/h 1 kn to mph 1 kn to ft/s

Feet per second

Feet per second (ft/s) is an imperial unit of speed used in ballistics, engineering, and some sports measurements. One foot per second equals approximately 0.682 mph or 1.097 km/h.

1 ft/s to m/s 1 ft/s to km/h 1 ft/s to mph 1 ft/s to kn

What Is Speed?

Speed is a scalar quantity that measures how fast an object moves — the rate of change of its position with respect to time. In physics, velocity is the vector equivalent that also includes direction. Speed is calculated by dividing the distance travelled by the time taken: speed = distance ÷ time.

Metric Speed Units

Metres per second (m/s) is the SI unit of speed, used in physics, engineering, and scientific research. Kilometres per hour (km/h) is the most widely used speed unit for road transportation — speed limits and vehicle speedometers in most countries display km/h. The conversion is straightforward: 1 km/h = 1000/3600 m/s ≈ 0.2778 m/s.

Imperial Speed Units

Miles per hour (mph) is the standard speed unit for roads in the United States, United Kingdom, and a few other countries. One mph ≈ 1.609 km/h. Feet per second (ft/s) is used in ballistics, some engineering applications, and sports measurements in the US.

Navigation

The knot (kn) equals one nautical mile per hour (approximately 1.852 km/h) and is the standard speed measure in aviation and maritime navigation. Wind speeds in weather reports for pilots and mariners are given in knots. The knot is historically linked to a method of measuring ship speed using a knotted rope thrown overboard.

Common References

Walking speed is roughly 5 km/h (3.1 mph). Highway speed limits typically range from 100 to 130 km/h (62 to 81 mph). The speed of sound in air is approximately 343 m/s (1,235 km/h or 767 mph).