Indianapolis 500 qualifying runs are timed over four laps. Each qualifying attempt covers 10 miles on the 2.5-mile Indianapolis Motor Speedway oval, with the driver completing four consecutive laps at speed. The car’s total elapsed time is converted into an average speed, which determines its position in the starting field.
The four-lap format has a long history. It was introduced in 1920, replaced by 10-lap qualifying from 1933 through 1938, and restored in 1939. It has remained the traditional distance ever since, although the surrounding qualifying schedule and advancement rules have changed repeatedly.
Two warm-up laps precede the timed run, so the complete appearance on track is longer than four laps. That detail causes a common mix-up: the warm-up laps do not count toward the official qualifying time. Another distinction is that the Indianapolis 500 race itself lasts 200 laps, or 500 miles; qualifying is only a four-lap speed trial.