by Guest » Wed May 04, 2005 3:40 am
A knot is a nautical mile per hour. A nautical mile is approximately one minute of arc at the equator or in latitude, and simplifies calculations in spherical trigonometry used to calculate great circle routes (shortest route on surface of earth).
The nautical mile was officially rounded to 1852 m in 1954, while a regular mile is 1609.344 m. Therefore a nautical mile is 1.15078 (regular) miles. The same ratio applies to knots and mph.