The vertical rise of a residential stair step should measure a maximum of 7 3/4 inches, according to the International Building Code that is used by most contractors. Each step's rise must vary no more than 3/8 inch from the other steps.
A step's minimum width is 36 inches, and the minimum tread length is 10 inches. The minimum headroom above the stairs is 6 feet 8 inches to accommodate the height of walkers as they climb the stairs. Handrails must be placed between 34 and 38 inches above a step's nose, which is the place where the tread and the riser meet.