Mile mile to diverge. Owing to the importance of the surveyor's rod in deeds and surveying undertaken under Henry VIII, decreasing the length of the rod by would have amounted to a significant tax increase. Parliament instead opted to maintain the mile of 8 furlongs (which were derived from the rod) and to increase the number of feet per mile from the old Roman value. The applicable passage of the statute reads: "A Mile shall contain eight Furlongs, every Furlong forty Poles, and every Pole shall contain sixteen Foot and half." The statute mile therefore contained 5,280 feet or 1,760 yards.
Metric mile 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