Mile (mi)
The mile, symbol mi, is an imperial unit of length traditionally defined as 5,280 feet or 1,609.344 meters. Its origin dates back to Roman times, from mille passus, meaning a thousand paces. The mile became standardized in England in the 16th century and is widely used in the United States, the UK, and some Commonwealth countries. Miles are common in road distances, running races, and nautical contexts (converted into nautical miles at sea). Despite global metric adoption, the mile’s enduring presence demonstrates its historical and practical significance in transportation and navigation.
Kilometer (km)
The kilometer, or km, is a unit in the metric system that equals 1,000 meters. It was established as part of the metric system during the French Revolution and soon became the default for measuring longer distances. The word “kilometer” is derived from the Greek for “thousand” (chilioi) and “measure” (metron). Kilometers are widely adopted for measuring travel distances, geographic features, maps, and sporting events in most countries. In contrast, the mile is still used in countries like the United States and the UK. The kilometer’s decimal structure makes calculations simple and has been essential to transportation planning, GPS technologies, and international measurement standards.