Convert from kilometer/hour to nautical mile/hour

Unit Definition (kilometer/hour)
The kilometre per hour (American English: kilometer per hour) is a unit of both speed (scalar) and velocity (vector). The unit symbol is km/h or km·h−1; however, the colloquial abbreviations "kph" and "kmph" are sometimes also used in English-speaking countries, in analogy to mph, although these are not in accordance with international scientific standards. In North American slang and military usage, km/h (as well as km) is commonly pronounced, and sometimes even written, as klicks or kays (K's), although these may also be used to refer to kilometres. The km/h is the worldwide most commonly used speed unit on road signs and car speedometers. Therefore, it is far more common in everyday usage than the proper SI unit of speed, m/s. Along with the kW·h, km/h is the most commonly used metric unit based on the hour, which is only a "non-SI unit accepted for use with the International System of Units" by the BIPM

Unit Definition (nautical mile/hour)
The knot is a unit of speed equal to one nautical mile per hour. Its kn abbreviation is preferred by American and Canadian maritime authorities, the Institute of Electrical and Electronics Engineers, and the International Bureau of Weights and Measures, however, the kt (knot) and kts (knots) abbreviations also are used. The knot is a non-SI unit accepted for use with the SI. World-wide, the knot is used in meteorology, and in maritime and aviation navigation — for example, a vessel travelling at 1 knot along a meridian, travels one-sixtieth of a degree of geographic latitude in one hour. Mariners first used the term knot denoting the measure of how many knots of line paid out in a given time using the chip log