Nautical mile
| Nautical mile | |
|---|---|
Historical definition – 1 nautical mile | |
| General information | |
| Unit of | length |
| Symbol | M, NM, or nmi |
| Conversions | |
| 1 M, NM, or nmi in ... | ... is equal to ... |
| metre | 1,852 |
| foot | ≈ 6,076.11549 |
| statute mile | ≈ 1.15078 |
| cable | 10 |
A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute (1/60 of a degree) of latitude at the equator, so that Earth's polar circumference is very near to 21,600 nautical miles (that is 60 minutes × 360 degrees). Today the international nautical mile is defined as exactly 1,852 metres (about 6,076 ft; 1.151 mi). The derived unit of speed is the knot, one nautical mile per hour.