Convert knot to mile/hour

knot

Definition: A knot (symbol: kn or kt) is a non-SI unit of speed at sea. It is defined as one nautical mile per hour, where a nautical mile is 1,852 meters. A knot is equal to 1.852 kilometers per hour and 1.15078 miles per hour.

History/origin: The term "knot" is derived from its former use as a measure on the log lines on ship logs (a navigation tool) which were used to measure ship speed through water. Knots would be tied into the rope on these lines at uniform intervals of approximately 47 feet, or 14.3 meters long. The knot has had various definitions throughout history. The United States and United Kingdom in particular used their own specific nautical miles up until 1954 and 1970 respectively. The US nautical mile is defined as 1,853.248 m while the UK Admiralty nautical mile is equal to 1853.184 m, compared to the international nautical mile of 1,852 m.

Current use: The knot is used worldwide in meteorology as well as in maritime and air navigation as a measure of speed of a vessel relative to the fluids in which they travel. Tidal streams, river currents, and wind speeds are also measured using knots.

mile/hour

Definition: The unit miles per hour (symbol: mph) is a measurement of speed in the imperial and United States customary systems. It expresses the number of statute miles traveled over the period of one hour. One mph equals exactly 1.609344 kilometers per hour (km/h).

Current use: Along with km/h, mph is most typically used in relation to road traffic speeds. It is most widely used in the United States, the United Kingdom, and their related territories. It is also used in the Canadian rail system, though the Canadian road systems use km/h.