Knot (kn) to Kilometres per hour (km/h)
One knot equals exactly 1.852 km/h — or about 1.151 miles per hour. While the US typically uses miles per hour for everyday speeds, knots are the standard in aviation, maritime navigation, and Coast Guard operations. Converting knots to km/h helps put ship and aircraft speeds in familiar perspective.
Frequently asked questions
1 knot = 1.852 km/h exactly. This is derived from the nautical mile (1852 meters) divided by 1 hour. In US customary terms, 1 knot ≈ 1.151 miles per hour.
20 knots × 1.852 = 37.04 km/h (about 23 mph). A typical cargo ship cruises at 12–15 knots (22–28 km/h), while a fast destroyer can reach 30+ knots (55+ km/h).
500 knots × 1.852 = 926 km/h (about 575 mph). Most commercial airliners cruise between 450 and 500 knots at altitude, just under Mach 1 (the speed of sound, approximately 767 mph at sea level).
The knot has been the maritime standard for centuries, originally measured using a knotted rope dragged behind a vessel. It was formalized in international maritime law and is used by the US Coast Guard, US Navy, and the IMO. The close relationship between knots and nautical miles makes navigation straightforward — 1 knot means covering exactly 1 nautical mile in 1 hour.