A mile is a unit of length. There are many different kinds of mile but mile on its own usually means the statute mile.
|Unit system||English unit|
|Symbol||mi or m|
|1 mi in ...||... is equal to ...|
|SI units||1609.344 m|
|nautical units||0.86898 nmi|
The nautical mile is used for sea or air travel.
The nautical mile was originally defined as one minute of arc along a line of longitude of the Earth. There are 60 minutes of arc in one degree or arc (60' = 1°). So there were 10,800 nautical miles from the North Pole to the South Pole.
Now the nautical mile is defined as 1,852 metres.
1 nautical mile = 1,852 metres (by definition) ≈ 6,076 feet ≈ 1.151 statute miles
The speed of a ship that travels one nautical mile in one hour is called one knot
The mile was first used by the Romans. It comes from the Latin phrase mille passus (plural: milia passuum). This means "one thousand paces". A pace is the distance each foot moves when taking one step.
1 Roman mile = 1,000 Roman paces (by definition) ≈ 1,479 metres ≈ 4,852 feet
Different miles have been used throughout history in various parts of the world. In Norway and Sweden, for example, a mil is a unit of length which is equal to 10 kilometres.