Available Speed units

• metre per second conversions

  Metre per second is the SI unit of speed. It is used in physics, engineering, and scientific contexts to express velocity, and serves as the reference unit for all speed calculations in this converter.

• kilometre per hour conversions

  Kilometre per hour is a unit of speed equal to one kilometre travelled in one hour. It is the most widely used unit for road speed limits, vehicle speedometers, and wind speeds in metric countries.

• mile per hour conversions

  Mile per hour is a unit of speed equal to one mile travelled in one hour. It is the standard unit for road speeds, vehicle performance ratings, and weather reports in the United States and United Kingdom.

• knot conversions

  A knot is a unit of speed equal to one nautical mile per hour, approximately 1.852 km/h. It is the international standard for maritime navigation, aviation, and meteorological wind speed reporting.

• foot per second conversions

  Foot per second is a unit of speed in imperial and US customary systems. It is used in ballistics, sports science, and engineering calculations that rely on US customary units.

• metre per minute conversions

  Metre per minute is a unit of speed expressing the distance in metres covered in one minute. It is used in industrial machinery, conveyor belt speeds, and slow-motion technical processes.

• kilometre per second conversions

  Kilometre per second is a unit of speed equal to 1,000 metres per second. It is used in astrophysics, rocket propulsion, and the measurement of planetary and cosmic velocities.

• mach (approx at sea level) conversions

  Mach is a dimensionless speed unit expressing the ratio of an object’s speed to the local speed of sound. At sea level, Mach 1 is approximately 343 m/s. It is used in aviation and aerodynamics to characterise high-speed flight regimes.

• centimetre per second conversions

  Centimetre per second is a unit of speed used in low-velocity applications such as biological locomotion studies, microfluidics research, and slow-moving mechanical systems.

• mile per minute conversions

  Mile per minute is a unit of speed equal to 60 miles per hour. It is occasionally used in motorsport, aviation briefings, and quick calculations for high-speed travel in imperial measurement systems.

Assumption: Mach uses an approximate sea-level reference (about 340.29 m/s).

Full Speed conversion matrix

About Speed

Units of speed

Real-world uses

Speed measurement is vital for transportation, athletics, meteorology, and physics. Road speed limits are posted in kilometres per hour or miles per hour. Aviation uses knots (nautical miles per hour) for airspeed and wind reporting. In athletics, sprint times translate to metres per second for biomechanical analysis. Meteorologists classify hurricanes by sustained wind speed, and network engineers measure data throughput in megabits per second.

History

Before reliable instruments, sailors estimated speed by tossing a wooden log overboard and counting knots on a trailing rope — giving rise to the unit "knot." The first practical speedometer was developed by the Croatian Josip Belusic in 1888. Ernst Mach lent his name to the ratio of an object's speed to the local speed of sound in the 1920s. Today, laser interferometry can measure speed changes of nanometres per second.

Common mistakes

A frequent error is converting between km/h and m/s by simply dividing or multiplying by 10 instead of the correct factor of 3.6 (1 m/s = 3.6 km/h). Many people also confuse knots with nautical miles — a knot is a speed (one nautical mile per hour), not a distance. Another common mistake is treating Mach number as a fixed speed, when it actually varies with altitude and temperature because the speed of sound changes.

Measurement standards

The SI unit of speed is metres per second (m/s), a derived unit requiring no independent definition. The knot is defined as exactly one nautical mile (1,852 metres) per hour and is sanctioned for maritime and aeronautical navigation by the International Civil Aviation Organization.

Did you know?

The fastest human-made object is the Parker Solar Probe, which reached 635,266 km/h (about 176 km/s) in 2024 during a close pass of the Sun — fast enough to travel from New York to Tokyo in under a minute.

Common values