Mile is a unit of length. In the inch-pound system of measurement customarily used in the United States, the unit used to measure land distances is the international statute mile. It is equal to 5,280 feet or 1,760 yards.
The mile was first used by the Romans. The Roman mile was about 5,000 feet long and had 1,000 paces, each 5 feet in length. The term mile comes from milia passuum, the Latin words for a thousand paces. In the metric system, the unit used to measure land distances is the kilometer. One mile equals 1.609 kilometers.
Distances on the sea are measured in nautical, geographical, or sea miles. The international nautical mile used primarily in the United States equals exactly 1.852 kilometers, or approximately 1.151 international statute miles. One international nautical mile equals almost exactly 1 minute of the circumference of the earth’s surface. The value of 1.852 kilometers per international nautical mile can be derived by dividing the approximate circumference of the earth—40,000 kilometers—by 360 degrees, dividing the result by 60 (the number of minutes in 1 degree), and rounding to three decimal places.
See also Knot; League; Weights and measures.
