Stair Stringer Calculator

Steps (risers)
Riser height
Total run
Stringer length
Angle

IRC: riser ≤ 7.75″, tread ≥ 10″, 2 × riser + tread between 24–25″. Most jurisdictions require 2 outer stringers + 1 middle for spans > 36″.

About this tool

Stair Stringer Calculator is a single-purpose utility on instant.tw, a free toolbox of calculators, converters, generators, and quick lookups. Everything works in your browser — nothing is uploaded, nothing is stored on a server unless explicitly noted.

Category: Trade & Construction Calculators. Browse more Trade & Construction Calculators tools.