Formula Three (Formula 3 or F3) is one of the classes of open-wheel formula racing. The various Formula 3 championships held in Australia, Europe, Asia and South America form an important step for many prospective Formula One drivers. The sport has traditionally been regarded as the stepping stone for F1 hopefuls and is the first point in a driver's career who is aiming at a professional career in racing rather than being amateur or enthusiast. Formula 3 is not cheap but is considered as a key investment in a young driver's future career.
Success in the sport may lead directly to a GP2 seat or even an F1 test or race seat. Formula 3 evolved from postwar auto racing, with lightweight tube-frame chassis powered by 500 cc motorcycle engines. The 500 cc formula was evolved in 1946 from low-cost "special" racing organized by enthusiasts in Bristol, England immediately before the Second World War. During the late 1950s, 500cc Formula 3 was overshadowed by Formula Junior for 1000 or 1100cc cars. In 1971, 1600cc engines with a restricted air intake were introduced and in 1974, two-litre engine rules were introduced, still with restricted air intakes. By the beginning of the 1980s, however, Formula 3 had evolved well beyond its humble origins to something closely resembling the modern formula.