BuildToolsHub US Construction Calculators

Stairs, Ramps & Access

Stair Calculator

Calculate rise, run, risers, and treads for straight stairs.

Loading tool…

Educational US estimate only. Not engineering, structural, code, or professional construction advice. Mix designs, codes, and local conditions vary — verify with licensed professionals and your building department.

Estimator methodology

BuildToolsHub takeoffs separate net measured quantities from ordered quantities. Ordered qty = net × condition-based waste, then rounded for plant or package sizes (e.g. ready-mix to the nearest 0.5 yd³).

  • Concrete bags: Quikrete / SAKRETE published yields (80 lb ≈ 0.60 ft³). Ready-mix contingencies follow ASTM C94 purchaser practice.
  • Rebar: CRSI published lb/ft tables; optional lap allowance ≈ 40× bar diameter (confirm with drawings).
  • Roofing: NRCA squares (100 ft²); pitch factor √(1+(rise/12)²); ~3 bundles/square for standard shingles.
  • Aggregates / fill: ASTM C29-style densities; swell/compaction allowances for haul and place volumes.
  • Masonry: BIA / NCMA common unit factors (e.g. ~1.125 CMU/ft² for 8×16 face).

Use the Order tab for a supplier call sheet and the Assumptions panel for the exact factors applied to this run.

Why use Stair Calculator

Enter total floor-to-floor rise to estimate number of risers, riser height, and tread run.

Building codes limit riser/tread dimensions and headroom—verify locally before cutting stringers.

How to use

  1. Enter job dimensions. Pick a pour/layout condition to set industry waste %, or choose Custom.
  2. Review Net vs Order on the Summary tab — order the rounded quantity, not net alone.
  3. Open the Order tab for a supplier checklist, then print, export CSV, or share the link.

Related searches

  • stair calculator
  • riser height
  • stair rise run
  • stringer layout
  • free stair calculator
  • online stair calculator
  • buildtoolshub construction calculator

About Stair Calculator

What is a comfortable riser height?

Often around 7–7.75 inches, within code maximums.

How many treads vs risers?

Typically one fewer tread than risers on a straight run between floors.

Does this include landings?

Straight-run math only; add landings as separate geometry.

Is this professional engineering advice?

No. Educational estimates only. Verify with a licensed professional and local codes.

Related tools