Knot (kn) to Kilometres per hour (km/h)
One knot equals exactly 1.852 km/h — a precise, internationally defined conversion based on the nautical mile (1852 metres). Converting knots to kilometres per hour is helpful when you want to relate maritime or aviation speeds to everyday road speeds. A modern container ship travelling at 20 knots, for instance, is covering 37 km/h — considerably slower than a motorway car.
Frequently asked questions
1 knot = 1.852 km/h exactly. This follows from the definition of the nautical mile: 1 nautical mile = 1852 metres, and 1 knot = 1 nautical mile per hour.
20 knots × 1.852 = 37.04 km/h. A typical cargo ship cruises at 12–15 knots (22–28 km/h), while a fast naval vessel or large ferry can reach 30 knots (55.6 km/h).
500 knots × 1.852 = 926 km/h. This is just below the speed of sound (approximately 1235 km/h at sea level). Long-haul passenger jets typically cruise between 450 and 500 knots (830–926 km/h) at altitude.
The knot has been the international standard for maritime speed since the age of sail, when sailors used a knotted rope (the "chip log") thrown overboard to measure speed. The unit was formalised in international conventions and is now embedded in IMO regulations, aircraft navigation rules, and weather services worldwide. The simplicity of knot-to-nautical-mile conversion for navigation has kept it in use to this day.