Knot (unit)

knot
An airspeed indicator, which shows speed in knots
General information
Unit system
  • meteorology
  • aviation
  • maritime
Unit ofspeed
Symbolkn, kt
Conversions
1 kn in ...... is equal to ...
   km/h   1.852
   mph   1.15078
   m/s   0.514444
   ft/s   1.68781

The knot (/nɒt/) is a unit of speed equal to one nautical mile per hour, exactly 1.852 km/h (approximately 1.151 mph or 0.514 m/s).[1][2] The ISO standard symbol for the knot is kn.[3] The same symbol is preferred by the Institute of Electrical and Electronics Engineers (IEEE), while kt is also common, especially in aviation, where it is the form recommended by the International Civil Aviation Organization (ICAO).[4] The knot is a non-SI unit.[5] The knot is used in meteorology, and in maritime and air navigation. A vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour.

  1. ^ Wragg, David W. (1973). A Dictionary of Aviation (first ed.). Osprey. p. 173. ISBN 9780850451634.
  2. ^ Bartlett, Tim (July 2008) [2003]. RYA Navigation Handbook. Southampton: Royal Yachting Association.
  3. ^ "ISO 80000-3:2006". International Organization for Standardization. Retrieved 20 July 2013.
  4. ^ International Standards and Recommended Practices, Annex 5 to the Convention on International Civil Aviation, "Units of measurement to be Used in Air and Ground Operations", ICAO, 4th Edition, July 1979.
  5. ^ "Non-SI units accepted for use with the SI, and units based on fundamental constants". SI brochure (8th ed.). International Bureau of Weights and Measures. The knot is defined as one nautical mile per hour. There is no internationally agreed symbol, but the symbol kn is commonly used.