The same structural job — carrying load safely from top to bottom — split out by build material so a wood-stringer question and a steel-stringer question get separate, correct formulas. If you're sizing generic stringer spacing or beam span, see Structural & Load Engineering instead. If you're picking finish surfaces, see Materials, Finishing & Cut-Lists.
About this category
How is this different from "Structural & Load Engineering"?
Structural & Load Engineering covers generic structural checks that apply across materials — stringer spacing, beam span, footing size, load capacity. This category takes those same structural jobs and works them out for a specific material, like concrete volume or steel plate thickness.
What's the difference between the Wood Stair Calculator and the 2x12 Stringer Board Calculator?
The Wood Stair Calculator is the full planner — lumber sizing and grade selection across the whole staircase. The 2x12 Stringer Board Calculator is a quick board-count tool for when you already know your stringer design and just need the count.
Do these include finish materials like tile or carpet?
No — these calculators size the structural material only (concrete, wood, steel, stone, etc). For treads, carpet, tile, paint and trim, see Materials, Finishing & Cut-Lists.