Stair takeoff starts with total rise. Select an integer riser count that satisfies the project requirements, derive actual riser height, then calculate tread count, total run, and stringer slope geometry.
Measure finished-floor total rise, choose an integer riser count that satisfies project requirements, calculate actual riser height, then derive tread count, total run, and stringer slope length.
Published: September 27, 2026
Last reviewed: September 27, 2026
Published by BuildYard. The guide reflects BuildYard's calculation methodology and editorial standards and does not replace project-specific professional advice.
Use finished-floor to finished-floor elevation, not rough framing height alone.
Finish thickness changes can alter the first and last riser.
Actual riser height = total rise ÷ number of risers.
Check every resulting dimension against the governing project/code requirements.
For a typical straight flight between levels, tread count is commonly one less than riser count.
Total horizontal run = tread count × selected tread depth.
Geometric stringer line = √(total rise² + total run²).
Add bearing, cuts, landings, and stock-length requirements separately.
Estimate welded wire reinforcement sheets from slab area, sheet dimensions, required laps, edge conditions, and whole-sheet layout.
Read guide →Steel, Lumber & FramingEstimate structural steel beam weight from specified section weight per foot and ordered length, including piece count and fabrication allowance.
Read guide →Steel, Lumber & FramingEstimate plywood sheets from net surface area, panel size, orientation, openings, edge support, and layout waste.
Read guide →Geometry example only; dimensions, landings, stringer sizing, and guards require project/code verification.
| Step | Calculation | Result |
|---|---|---|
| Riser height | 105÷15 | 7 in |
| Treads | 15−1 | 14 |
| At 10 in tread | 14×10 | 140 in run |
| Slope line | √(105²+140²) | 175 in |
Current manufacturer data, supplier specifications, drawings, field measurements, applicable codes, permit requirements, and qualified professional guidance can take priority over a general-purpose planning estimate.