Concrete Formwork Calculator

Calculate formwork area, lateral pressure, lumber quantities, and costs for walls, columns, beams, and slabs.

Total length
Thickness or width
Height or depth
Number of identical elements
Default is 10%
At placement
Vertical placement
Plywood/Form cost
Times reused
Horizontal
Vertical
L W H

How to Use This Tool

  • Select the Element Type (Wall, Column, Beam, Slab, or Footing).
  • Enter dimensions. Use the Imperial/Metric toggle at the top to switch units.
  • Input your Concrete Temperature and Pour Rate to calculate ACI 347 lateral pressure.
  • The 3D shape updates in real-time. Results populate instantly as you type.

Formulas Used (ACI 347)

  • Wall Area: 2 × Length × Height
  • Column Area: Perimeter × Height
  • Lateral Pressure: P = 150 + 9000 × Cc × (R / T), capped at 2000 psf and 150 × H (hydrostatic).
  • Form Ties: Total Area / (Horizontal Spacing × Vertical Spacing)
  • Studs: Perimeter / 2ft spacing × Height
  • Release Agent: Total Area / 250 sq ft per gallon

Material Recommendations

  • Plywood: Best for 3-5 uses. Use 3/4" tongue and groove for walls/columns.
  • Steel: Ideal for 50+ uses. High initial cost but lowest cost per use for large projects.
  • Accessories: Don't forget form release agent (apply 24 hrs before pouring), form ties (snap ties for walls, through-ties for heavy pressure), and nail plates.