Definition
A unit of distance used in aviation and marine navigation, equal to 1,852 meters or approximately 6,076 feet. One nautical mile corresponds to one minute of arc of latitude along any meridian of the Earth.
Plain English
A unit pilots use to measure distance. One nautical mile is a bit longer than one statute mile (the kind used on roads) — about 1.15 times as long.
Context Anchor
Seen on aviation charts, in airspace descriptions, in navigation planning, and when measuring distance from airports or fixes.
Derivation
From the Latin navis (ship). The unit comes from sea navigation, where it was tied directly to the size and shape of the Earth — one nautical mile equals one minute of latitude. That link to the Earth's geometry is why it remains the standard for aviation and marine use.
Why Pilots Care
All U.S. aviation charts, performance data, and airspace dimensions are expressed in nautical miles, so pilots must use this unit for accurate flight planning and regulatory compliance.
Intuition Check
Do not assume a nautical mile is the same as a regular road mile. One nautical mile is about 1.15 regular miles, and in aviation it is the normal unit for navigation distance.
Example Sentence 1
The destination airport is 85 nautical miles to the southwest.