Kilometers, miles and nautical miles are all units of measurement used to measure distance. While they all measure distance they are not interchangeable and each has its own specific use case.
Kilometers (km) are the most common unit of distance used in the metric system. One kilometer is equal to 1000 meters. Kilometers are used throughout the world except in the United States and the United Kingdom. Kilometers are used to measure distance in most land-based travel such as driving or walking.
Miles (mi) are a unit of distance used in the United States and the United Kingdom. One mile is equal to 1.60934 kilometers. Miles are used to measure distance in land-based travel such as driving or walking in the United States and the United Kingdom. Miles are also used in aviation to measure distance but nautical miles are more commonly used.
Nautical miles (nm) are used primarily in maritime and aviation navigation. One nautical mile is equal to 1.852 kilometers or approximately 1.15078 miles. Nautical miles are used to measure distance between two points on the surface of the Earth or on a nautical chart.
When to use aach unit: When choosing which unit of measurement to use consider the context in which the measurement is being used. For example, if you are measuring the distance between two cities for a road trip, kilometers or miles would be appropriate. If you are measuring the distance between two points on a map or nautical chart, nautical miles would be more appropriate. In aviation, nautical miles are the most commonly used unit of measurement.