Metric Conversions
Metric Conversions

Knots (kn)

A knot is a unit of speed equal to one nautical mile per hour. It precisely corresponds to 1.852 kilometers per hour or 0.51444 meters per second. The knot is internationally recognized for maritime and aviation speed measurements and is defined using the international nautical mile of exactly 1852 meters [nist-si-guide].

Origin

The knot originated from the practice of measuring speed at sea using a 'log line' with knots tied at regular intervals. The term and unit were standardized with the adoption of the international nautical mile in 1929 by the International Hydrographic Organization [nist-si-guide].

Worldwide Use

Knots are the standard speed unit in global maritime navigation and aviation. Countries and organizations like the International Maritime Organization (IMO) and International Civil Aviation Organization (ICAO) mandate its use for vessel and aircraft speed reporting [nist-si-guide].

Common References

  • A typical commercial ship cruises at about 20 knots
  • Small recreational sailboats often travel near 5 knots
  • Airliners approach landing speeds around 130 knots
  • A strong ocean current may reach speeds of 3 to 5 knots
Knots → Meters per Second1 kn = 0.5144 m/sKnots → Kilometers per Hour1 kn = 1.852 km/hKnots → Miles per Hour1 kn = 1.1508 mphKnots → Feet per Second1 kn = 1.6878 ft/sKnots → Speed of Light1 kn = 0 cKnots → Speed of Sound1 kn = 0.0015 MachKnots → Centimeters per Second1 kn = 51.4444 cm/sKnots → Millimeters per Second1 kn = 514.444 mm/sKnots → Inches per Second1 kn = 20.2537 in/sKnots → Yards per Second1 kn = 0.5626 yd/sKnots → Kilometers per Second1 kn = 0.0005 km/sKnots → Miles per Second1 kn = 0.0003 mi/sKnots → Meters per Minute1 kn = 30.8666 m/minKnots → Kilometers per Minute1 kn = 0.0309 km/minKnots → Miles per Minute1 kn = 0.0192 mi/minKnots → Feet per Minute1 kn = 101.2685 ft/minKnots → Inches per Minute1 kn = 1,215.222 in/minKnots → Yards per Minute1 kn = 33.7562 yd/minKnots → Meters per Hour1 kn = 1,851.9984 m/hKnots → Miles per Day1 kn = 27.6187 mi/dKnots → Kilometers per Day1 kn = 44.448 km/dKnots → Nautical Miles per Hour1 kn = 1 nmi/hKnots → Furlongs per Fortnight1 kn = 3,093.2925 fur/fnKnots → First Cosmic Velocity1 kn = 0.0001 v1Knots → Second Cosmic Velocity1 kn = 0 v2Knots → Third Cosmic Velocity1 kn = 0 v3Knots → Earth1 kn = 0 v⊕Knots → Speed of Sound in Water1 kn = 0.0003 swKnots → Mach (Sea Level)1 kn = 0.0015 MaKnots → Beaufort 1 (Light Air)1 kn = 0.6431 Bft 1Knots → Beaufort 6 (Strong Breeze)1 kn = 0.0418 Bft 6Knots → Beaufort 12 (Hurricane)1 kn = 0.0157 Bft 12Knots → Leagues per Hour1 kn = 0.0004 lea/hKnots → Dekameters per Second1 kn = 0.0514 dam/sKnots → Hectometers per Second1 kn = 0.0051 hm/sKnots → Megameters per Second1 kn = 0 Mm/sKnots → Gigameters per Second1 kn = 0 Gm/sKnots → Terameters per Second1 kn = 0 Tm/s