Stair Calculator
Construction & Home ImprovementCalculate the number of steps, stringer length, and comfort rating for a staircase from its total rise and target step dimensions.
Number of Steps
Number of equal risers needed to cover the total rise.
Actual Step Rise
7.200
Exact rise per step once the total rise is divided evenly.
Stringer Length
176.82
Length of the diagonal stringer board, from the Pythagorean theorem.
Comfort Check (2R + T Rule)
Comfortable
Checks 2 times the actual rise plus the run against the widely used 24 to 25 inch stair comfort guideline.
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Creators
Odeh Ahwal0people find this calculator helpful
Views
Helpful
Saved
Embeds
Construction & Home Improvement calculators
Frequently Asked Questions
What is the 2R + T comfort rule?
Twice the step rise plus the step run should total about 24 to 25 inches, a widely used stair ergonomics guideline. It balances a person's natural stride length against a comfortable, safe climbing angle, since a stair with too much rise per step feels steep and tiring, while too little rise per step with a long run feels awkward.
Why does the actual rise differ slightly from the target rise?
The number of steps must be a whole number, so the total rise is divided by the nearest whole number of steps at the target rise, which usually results in an actual rise slightly different from, but very close to, the originally targeted value.
Does this meet building code requirements?
This checks stair comfort, not code compliance. Building codes set their own maximum riser height and minimum tread depth, commonly around 7.75 inches maximum rise and 10 inches minimum run in the US residential code, but always confirm the exact figures for your local jurisdiction.
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