Knot (speed)

The knot is a measure of the speed of ships and aircraft. One knot is equal to one nautical mile per hour. Since a nautical mile is slightly longer than a statute mile, an object traveling at one knot is moving slightly faster than an object traveling at one statute mile per hour. (1 knot = 1.150779 statute miles per hour = 1.852 kilometers per hour)

The term originated in the days of sail, when a ship's speed was roughly measured with an apparatus consisting of a float, an hourglass, and a knotted line.

The term is sometimes erroneously seen as "knots per hour."