Stair Formwork Calculator

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Stair geometry
mm
mm
mm
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Forms
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Stair formwork1500 mm9 risers · waist 150 mm · 1200 mm widesoffit and riser formsmyconstructioncalculator.com
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Results

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Total formwork area
5.93m²
Soffit (sloping)3.00 m²
Stringer sides1.13 m²
Riser boards (9)1.80 m²
Sheets3 sheets, 15% waste incl.
Concrete (flight)0.675 m³
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Working
  1. 9 risers of 166.7 mm; 8 treads; run 2.00 m; slope length 2.50 m
  2. Soffit = slope length × width = 2.50 × 1.20 = 3.00 m²
  3. Each side = slope × waist + risers × ½ × R × G = 0.56 m² × 2
  4. Riser boards = 9 × R × width = 1.80 m²
  5. Sheets = ⌈5.93 × 1.15 ÷ 2.98⌉ = 3

Results are estimates for planning and material ordering only. They are not a substitute for structural design or approval by a qualified engineer. Read the full disclaimer.

Stair Formwork Calculator byMy Construction Calculator: free construction calculators with the working shown.