Stair Calculator — Rise, Run, Treads & Stringers
Spec no. 13How to use
Measure the total rise (floor-to-floor height) in inches. Building codes keep each riser at 7–7.75 inches ideally; the calculator divides the rise evenly and checks comfort. Treads are typically 10–11 inches deep. Stringer length is the diagonal of total rise and run plus a little extra for cuts.