Stair Designer — free 3D stair model + OBJ export

Stairs Calc Stair Designer Meets IRC 2021

Design

Stair type

Material

Total rise

Finished floor to finished floor.

Target riser height

Rounded to a whole number of equal risers, kept within code.

Tread run (going)

The depth you step on, not counting the nosing.

Stair width

Stringer mount

Railings

Left side

Right side

Rail height

Top of the rail above the nosing line. Codes target 34–38″.

A guard fills the side with your chosen infill — balusters, glass, cable, or horizontal bars. Renders live in 3D and is included in the .obj export.

Advanced

Nosing

Tread thickness

Upper floor thickness

Headroom

Risers

Building code