100 meters is approximately 328.08 feet, 109.36 yards or 0.062137 miles. It is exactly 0.1 kilometer and one-fifth of 500 meters.
On an athletics track, the marked 100-meter sprint provides a familiar reference: it runs along the straight. Do not assume that any visually straight section or any pair of painted lines is exactly 100 meters; use the correct event markings.
The same measured distance applies whether you walk or run it. The activity changes the time, not the route's length.