Free stair calculator for perfect measurements. Calculate number of stairs, riser height, and tread depth for safe, code-compliant staircases. Instant results for residential and commercial projects.
Calculate the exact number of stairs, riser height, and tread depth for your staircase project. Enter your measurements to get code-compliant dimensions.
Ideal range is 6.5-7.5 inches for comfortable stairs
Riser Height (inches)
6.75
Tread Depth (inches)
9.60
Total Run (inches)
144.00
Calculation Formulas
Number of Stairs = Ceiling(Total Height ÷ Riser Height)
= Ceiling(108 ÷ 7) = 16
Actual Riser Height = Total Height ÷ Number of Stairs
= 108 ÷ 16 = 6.75
Tread Depth = Total Run ÷ (Number of Stairs - 1)
= 144 ÷ 15 = 9.60
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