What is metre per second?

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.

Real-world uses

Metres per second is the SI unit of speed used in physics, engineering, and scientific research. Wind speed in meteorological data, projectile velocities, and fluid flow rates are expressed in m/s. The speed of sound at sea level is approximately 343 m/s.

History

As an SI derived unit, metres per second became the standard scientific speed unit with the adoption of the SI system in 1960. It naturally combines the base units of length (metre) and time (second).

Common mistakes

Forgetting to convert from km/h—divide by 3.6, not by 3.0 or 60. Also, confusing velocity (vector with direction) with speed (scalar magnitude), both expressed in m/s but with different physical meanings.

What is kilometre per second?

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.

Real-world uses

Kilometres per second is used in astronomy and astrophysics for orbital velocities, galaxy recession speeds, and asteroid approach velocities. Earth orbits the Sun at about 29.78 km/s, and escape velocity from Earth is about 11.2 km/s.

History

Kilometres per second became a standard unit in celestial mechanics and astrophysics during the 20th century. It provides convenient numbers for solar system velocities, while larger cosmic speeds are often expressed as fractions of the speed of light.

Common mistakes

Forgetting the enormous scale—1 km/s = 3,600 km/h. A common error is treating km/s figures as if they were km/h. Also, confusing orbital speed with escape velocity, which are related but different concepts.

When is this conversion used?

Converting metre per second to kilometre per second is useful in the speed domain when comparing values across different measurement standards or applying formulas that require a specific unit.

Worked examples

1 metre per second = 0.001 kilometre per second

1 kilometre per second = 1,000 metre per second

How to convert metre per second to kilometre per second

To convert metre per second to kilometre per second, multiply the value by 0.001.

To convert kilometre per second back to metre per second, multiply by 1,000.

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.

Quick reference: metre per second to kilometre per second

metre per second	kilometre per second
0.1	0.0001
0.5	0.0005
1	0.001
2	0.002
5	0.005
10	0.01
25	0.025
50	0.05
100	0.1
250	0.25
500	0.5
1,000	1

Common values

	metre per second	kilometre per second
Walking speed	1.4 metre per second	0.0014 kilometre per second
City speed limit	13.9 metre per second	0.0139 kilometre per second
Highway driving	31.3 metre per second	0.0313 kilometre per second
Commercial aircraft	250 metre per second	0.25 kilometre per second
Speed of sound (sea level)	340.29 metre per second	0.34029 kilometre per second

Available Speed units

More metre per second conversions

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