A flight of stairs typically has between 12 and 16 steps on average. The exact number can vary depending on factors such as the height of the ceiling, building codes, and the intended use of the staircase. For example, an 8-foot ceiling usually results in about 12-15 steps, while higher ceilings like 9 or 10 feet might have 15-19 steps. The average step height is around 7 to 7.75 inches, with step depth about 10 inches and step width about 36 inches in most modern constructions.