Metric mile
A metric mile is a distance which approximates one statute mile (1609.344 m) at a round figure of metres (the SI or metric unit of length). The term is most commonly used in track running and swimming.
In track running, the 1500 m race became the standard middle distance race in Europe in the late 19th century,[1] and has been the standard distance in the Olympic Games since 1896. The distance of the race is sometimes referred to as a metric mile.[2]
Prior to metrication, many tracks in the United States and the Commonwealth of Nations were constructed to the specifications of one quarter of a mile, 440 yards (402.336 m). Thus when the mile was run, the race was a four lap race. The Commonwealth officially converted to metric in the mid-1960s. The United States adopted metric rules in the mid to late 1970s, though some tracks are still constructed to be a quarter of a mile in length requiring calibrated painted lines to run metric races.
Even in countries like the U.S. which do not embrace the metric system, most running tracks now have a lap distance of 400 metres in the innermost lane. The final leg of a distance medley relay uses a four lap 1600 m leg; The standard middle distance in many United States high school competitions is 1600 m and this distance is sometimes referred to as a metric mile as well.
In swimming, the 1500 m (or 1650 yards) race is commonly referred to as "the swimmer's mile", and is often the longest distance swum by competitors in a pool. The standard distance triathlon also employs the swimmer's mile, except in open water instead of a pool.