Based on the Earth
A nautical mile is defined as exactly 1,852 meters, which is approximately one minute of latitude. Because it ties directly to the Earth's coordinates, navigation in nautical miles lines up neatly with charts — one degree of latitude is about 60 nautical miles.
Knots Are Speed
A knot is one nautical mile per hour. So a ship traveling 20 knots covers 20 nautical miles in an hour, or about 37 km/h. Knots are used universally in aviation and maritime contexts regardless of a country's land measurement system.
Comparing the Miles
| Unit | Meters |
|---|---|
| 1 statute mile | 1,609.34 |
| 1 nautical mile | 1,852 |