A knot is a unit of speed that’s equal to one nautical mile per hour. Worldwide, knots are used to describe the speed of a private jet, a ship’s speed on the water, or for meteorological purposes.

Since 1969, the Federal Aviation Regulations (FAR), has stated that distances flown and speeds of aircrafts were to be described in nautical miles and knots, respectively. Prior to 1969, distances were reported in statute miles and the speed of a private jet in miles per hour.

Converting a Knot

1 international knot is equal to the following:

  • 1 nautical mile per hour
  • Nearly 20.254 inches per second
  • Approximately 1.15 miles per hour
  • Exactly 1.852 kilometers per hour
  • Roughly 0.514 meters per second

In terms of length, 1 international knot is 1852 meters long.

Knot Origins

Prior to the mid-19th century, the speed of ships travelling on the sea was measured using a chip log. The chip log was basically a wooden panel with a rope attached to it. Knots were tied along the rope. Each knot was placed just over 47 feet apart from each other. To determine the speed, a sailor would case the rope overboard and allow the knots to slide through their fingers. Using a 30-second hourglass, the sailor would calculate how many knots would pass by during that time period.