The
knot is a unit of
speed equal to one
nautical mile (1.852 km) per hour, approximately 1.151 mph. The
ISO Standard symbol for the knot is
kn. The same symbol is preferred by the
IEEE;
kt is also common. The knot is a non-
SI unit that is "accepted for use with the SI". Worldwide, the knot is used in
meteorology, and in
maritime and
air navigation—for example, a vessel travelling at 1 knot along a
meridian travels approximately one
minute of geographic
latitude in one hour.