Stair Calculator
Calculate stair dimensions \u2014 rise, run, number of steps, and total length for building code compliance.
Number of Risers
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Riser Height
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Tread Depth (Run)
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Total Run Length
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Stringer Length
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Stair Angle
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How It Works
Stairs are calculated using building code standards. The ideal rise is ~7 inches and tread depth ~11 inches. The number of risers is determined by dividing total rise by ideal rise and rounding up. Tread depth uses the 2R + T = 25 rule (comfort formula).
About this Calculator
The Stair Calculator is a free, easy-to-use tool for rise, run, step. Simply enter your values and get instant, accurate results — no signup required. All calculations run locally in your browser, so your data stays completely private.
Privacy Note: All calculations are performed locally in your browser. No data is ever sent to a server or third party.