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Stair Calculator
Calculate the number of steps, riser height, tread run, stringer length and angle for a staircase, checked against IRC limits.
Stair Calculator
StepsRiser 7.714 in · total run 130 in (10.83 ft)
Stringer length
14.08 ft
Angle
39.7°
Comfort (2R + T)
25.4 in (ideal 24–25)
Headroom needed
≥ 6 ft 8 in
IRC R311.7: max riser 7¾ in, min tread 10 in, riser variation ≤ ⅜ in, headroom 6 ft 8 in. Check local codes; commercial stairs are stricter (7 in / 11 in).
Planning estimates only. Building codes, loads and material specs vary — have a licensed engineer or contractor confirm quantities and safety requirements. Disclaimer
Important
Quantity estimates for planning and ordering. Structural members, reinforcement and footings must be designed by a qualified engineer to local code.
Frequently asked questions
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