How to use the formwork area calculator
Choose a column, beam, wall or slab and only the size fields that member needs stay on screen. Enter those sizes and the count and the page unfolds the shape face by face, totals the formwork area in square feet with square meters in parentheses, and then applies your opening deduction and allowance. The first result line prints the unfolding it used.
A column is its section perimeter times its height, a beam is the soffit width plus twice the depth times the length, a wall is both faces, and a slab is the soffit plus the edge strips. Column and beam sections and slab thickness go in inches, lengths and heights in feet. All of these are geometry rather than a standard, and the page is current as of October 2026.
A published formwork allowance percent was not confirmed in an authoritative source, so no value is suggested and only your percent is applied. Plywood sheet counts, shoring quantities and reuse-based cost allocation are not covered. This calculator is for reference and does not replace design. Review by a qualified engineer is required.
Frequently asked questions
A column is counted as its section perimeter times its height, a beam as two sides plus the soffit, a wall as both faces, and a slab as the soffit plus its edge strips. The unfolding used is printed on the first result line so you can see what was added.
A published formwork allowance was not confirmed in an authoritative source, so none is suggested here and only the percent you type is applied to the area after deductions. Reuse-based cost allocation is not covered either.
Yes. A slab counts only the soffit and the edge strips, because the top surface takes concrete rather than formwork. If faces meeting walls or beams should come off, put them in the deducted area field.