text: how is nautical mile calculated?   nautical mile n. (abbr. nm) a unit of length used in sea and air navigation, based on the length of one minute of arc of a great circle, especially an international and u.s. unit equal to 1,852 meters (about 6,076 feet). also called sea mile.  to convert from miles (nautical) to:  feet, multiply by 6076.115.  kilometers, multiply by 1.852.  meters, multiply by 1852.  miles (statute), multiply by 1.1516.  yards, multiply by 2025.37.   the international standard definition is: 1 nautical mile = 1852 metres (exactly).