knot (kn)
1 knot = 0.51444444 metres per second
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.
Notes: Nautical speed
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.
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.
How to convert knot to metre per second
To convert knot to metre per second, multiply the value by 0.51444444.
Conversion formula (from base unit)
x * 0.5144444444
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.
| knots | metres per second |
|---|---|
| 0.1 | 0.05144444 |
| 0.5 | 0.25722222 |
| 1 | 0.51444444 |
| 2 | 1.02888889 |
| 5 | 2.57222222 |
| 10 | 5.14444444 |
| 25 | 12.86111111 |
| 50 | 25.72222222 |
| 100 | 51.44444444 |
| 250 | 128.6111111 |
| 500 | 257.2222222 |
| 1,000 | 514.4444444 |
Common values
| knots | metres per second | |
|---|---|---|
| Walking speed | 2.72138229 knots | 1.4 metres per second |
| City speed limit | 27.01943845 knots | 13.9 metres per second |
| Highway driving | 60.84233262 knots | 31.3 metres per second |
| Commercial aircraft | 485.96112315 knots | 250 metres per second |
| Speed of sound (sea level) | 661.47084239 knots | 340.29 metres per second |
Full knot conversion table
| Unit | Value | Factor |
|---|---|---|
| metre per second | 1 kn = 0.51444444 m/s | × 0.51444444 |
| kilometre per hour | 1 kn = 1.852 km/h | × 1.852 |
| mile per hour | 1 kn = 1.15077945 mph | × 1.15077945 |
| foot per second | 1 kn = 1.68780986 ft/s | × 1.68780986 |
| metre per minute | 1 kn = 30.86666666 m/min | × 30.86666666 |
| kilometre per second | 1 kn = 0.00051444 km/s | × 0.00051444 |
| mach (approx at sea level) | 1 kn = 0.00151178 Ma | × 0.00151178 |
| centimetre per second | 1 kn = 51.44444444 cm/s | × 51.44444444 |
| mile per minute | 1 kn = 0.01917966 mi/min | × 0.01917966 |