Question: what is the standard size for stairs?
Answer: The stair's width usually varies depending on the type of building the staircase is in, but for a normal residence, the standard tends to be 3 feet, 6 inches (106.7 cm). The minimum, in most places, is 2 feet 8 inches (81.3 cm). If a staircase exceeds 44 inches (111.8 cm), handrails are required for both sides.