On average, a single flight of stairs consists of about 12 to 16 steps, with a common estimate being around 15 steps per flight. Multiplying this average by 110 flights of stairs gives an estimate of approximately 1,650 steps in total for 110 flights of stairs. This estimate can vary depending on ceiling height, building codes, and architectural design, but 15 steps per flight is a reasonable assumption for a typical building stairway.