You should also measure the ceiling height. [2] X Expert Source Lui ColmenaresHandyman Expert Interview. 18 August 2020.
Headroom heights usually aren’t regulated by building codes, but your local building code may have recommendations for stair headroom, so be sure to check. For instance, if the total rise is 114 inches (290 cm), subtract 6 feet (1. 8 m), which is 72 inches (180 cm), to account for the headroom. This will leave you with a rise of 42 inches (110 cm).
If the rise is 42 inches (110 cm) (after subtracting 6–7 feet (1. 8–2. 1 m) for headroom) and you want larger stairs, for example, divide 42 by 6. Your staircase will have 7 stairs. If dividing the height to the second floor by your preferred height for the riser does not give you a whole number, round your calculation up if the decimal is larger than 0. 5 or down if the decimal is smaller than 0. 4.
The depth of each stair has to be enough for a person to safely walk up. [5] X Expert Source Lui ColmenaresHandyman Expert Interview. 18 August 2020.
This is the same as the total width of the staircase as well. For a specific minimum width, contact your local government about the building code for stairs.
For instance, if the run is 10 inches, square 10 by multiplying it by itself to get 100. If the individual stair rise is 7 inches, square 7 by multiplying it by itself to get 49 inches. Add 100 and 49 to get 149. Then, find the square root of 149, which is 12. 206, meaning the length of each stringer will be 12. 2 inches.
