What is knot?

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.

Real-world uses

Knots are the universal speed unit in maritime navigation and aviation worldwide, regardless of whether a country uses metric or imperial. Ship speeds, ocean currents, wind speed in aviation weather (METAR) reports, and jet stream velocities are all given in knots.

History

The knot originates from the 17th-century practice of measuring ship speed by throwing a log overboard attached to a rope with knots tied at regular intervals. Sailors counted how many knots paid out in a fixed time (measured by a sandglass).

Common mistakes

Saying "knots per hour"—a knot already means nautical miles per hour, so adding "per hour" is redundant and incorrect. Also, confusing knots with km/h: 1 knot ≈ 1.852 km/h.

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.

When is this conversion used?

Converting between knot and metre per second is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region.

Worked examples

1 knot = 0.51444444 metre per second

1 metre per second = 1 metre per second

How to convert knot to metre per second

To convert knot to metre per second, multiply the value by 0.51444444.

To convert metre per second back to knot, multiply by 1.94384449.

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: knot to metre per second

knotmetre per second
0.10.05144444
0.50.25722222
10.51444444
21.02888889
52.57222222
105.14444444
2512.86111111
5025.72222222
10051.44444444
250128.6111111
500257.2222222
1,000514.4444444

Common values

knotmetre per second
Walking speed2.72138229 knot1.4 metre per second
City speed limit27.01943845 knot13.9 metre per second
Highway driving60.84233262 knot31.3 metre per second
Commercial aircraft485.96112315 knot250 metre per second
Speed of sound (sea level)661.47084239 knot340.29 metre per second