How long does a set of stairs need to be?
It will yield a staircase with 14 risers. All staircases have one more riser than they do treads. This means you will have 13 treads for a total length of 130 inches or 10 feet 10 inches. You must also figure in a minimum three-foot landing or clear floor area at the bottom of the steps.
The general rule (in the US) is 7-11 (a 7 inch rise and 11 inch run). More exactly, no more than 7 3/4 inches for the riser (vertical) and a minimum of 10 inches for the tread (horizontal or step). You can find some more information here as well on other stair-related dimensions.
- Use a calculator to calculate the stair riser length or the number of steps you'll need. Divide the height from the first floor to the top of the second floor by a predetermined height of your choice for the riser. The typical height of a riser is 6 or 7 inches (15 to 17.5 cm).
- Stair riser heights shall be 7 inches (178 mm) maximum and 4 inches (102 mm) minimum. Stair tread depths shall be 11 inches (279 mm) minimum. The riser height shall be measured vertically between the leading edges of adjacent treads.
- A flight of stairs shall not have a vertical rise greater than 12 feet (3658 mm) between floor levels or landings. The width of each landing shall not be less than the stairway served. Every landing shall have a minimum dimension of 36 inches (914 mm) measured in the direction of travel.
Stair riser heights shall be 7 inches (178 mm) maximum and 4 inches (102 mm) minimum. Stair tread depths shall be 11 inches (279 mm) minimum. The riser height shall be measured vertically between the leading edges of adjacent treads.
- Stair Width: 36 Inches Minimum (Not Including Handrails) Translated: This means that any stairs must be at least 3 feet wide, measured from side to side as if you are walking up or down the stairs.
- A nosing is not required where the tread depth is a minimum of 11 inches (279 mm). The opening between adjacent treads is not limited on stairs with a total rise of 30 inches (762 mm) or less.
- There are no restrictions when it comes to width, but standard flights measure 860mm, and for a main staircase it is agreed that a width of between 800mm and 900mm works best. For secondary staircases a minimum width of 600mm is recommended.
Updated: 21st September 2018