Surface and trim material estimates — treads, risers, nosing — kept separate from structural sizing. If you're framing the stair itself, see Structural & Load Engineering or Material-Specific Structural instead.
About this category
What's the difference between this category and "Material-Specific Structural"?
Material-Specific Structural sizes the load-bearing frame of the stair itself (stringers, footings) by build material. This category sizes the finish surfaces and trim that go over that frame once it's built — treads, carpet, tile, paint, nosing.
Do these calculators account for waste and cut allowance?
Where relevant — carpet, tile, and runner calculators build in a pattern or cut allowance so the quantity reflects what you'd actually order, not just the raw surface area.
Which calculator do I use for trim?
Stair Nose Trim covers the front edge of the tread, Stair Baseboard / Skirting Trim covers the wall line, and Riser Trim covers the vertical face — pick based on which surface you're finishing.