Wall formwork area

How it is calculated

Contact area = 2 × wall length × height + 2 × wall thickness × height.

Keep the full result when using it in another calculation. Results show up to three decimal places; very small positive results use scientific notation (for example, 1e-6). No extra material for waste is added.

List the formed faces

Enter the wall length, the height of the formed wall, and its thickness. The model includes two long faces, each length by height, plus two end faces, each thickness by height. It excludes the top and bottom faces.

If a face is not formed, or an opening needs to be deducted, this calculator does not adjust for it. Calculate omitted faces or openings separately to match the actual form layout.

Separate contact area from panel count

For a wall 20 ft long, 4 ft high, and 0.5 ft thick, the two long faces total 2 × 20 × 4 = 160 ft². The two ends total 2 × 0.5 × 4 = 4 ft², giving 164 ft² of concrete-contact area.

The result measures surface area, not the number of form panels, sheets, ties, or braces to purchase. Panel sizes, reuse, openings, and formwork design require information that this calculation does not use.

Before you use the result

• Both full wall sides and both ends are formed. The calculation excludes the top and bottom faces and makes no deduction for openings.
• The result is the area of formwork touching concrete, not the number of panels to buy. It does not plan panel cuts or reuse, or determine concrete pressure, bracing, removal time, or formwork design.

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