Stair Layout
Divide total rise into equal risers under an entered height limit.
Your numbers
Riser count
Geometry sketch only; not a building-code check. Headroom, landings, guards and local accessibility rules are excluded.
Scenario comparison
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Formula
Use N = ceil(H/r) and T = N−1. H is total rise and r is the preferred maximum riser height in the same unit. ceil rounds up; T counts treads before the upper landing. Actual riser height is H/N.
Divide total rise into equal risers under an entered height limit.
Worked example
- Total rise (mm)
- 2800
- Maximum preferred riser (mm)
- 180
- Tread going (mm)
- 250
- Riser count
- 16
- Actual riser height
- 175 mm
- Treads before upper landing
- 15
- Straight horizontal run
- 3,750 mm
Scope and limitations
Geometry sketch only; not a building-code check. Headroom, landings, guards and local accessibility rules are excluded.
Inputs are checked for missing values and allowed ranges. A result outside the finite numeric range is not displayed. Rounding affects display, while the calculation uses the model’s numeric precision.
Check your units and assumptions before relying on a result. Changing a label does not convert a currency or physical unit.
Formula version: fd4c497d06d8 · Example checked: