Work out formwork area instantly with clear inputs, formula shown and shareable results.
Formwork is measured as the area of concrete surface in contact with the shuttering. A slab contributes its soffit, a downstand beam contributes both sides over its depth below the slab, and columns contribute their full perimeter times height. It is usually the largest labour item in in-situ concrete work.
Total contact area
Area = slab soffit + 2 x beam length x beam depth + column areas
Area = slab soffit + 2 x beam length x beam depth + column areas. Formwork is measured as the area of concrete surface in contact with the shuttering.
Only where the beam is wider than the slab opening it frames. Otherwise the soffit strip is normally measured within the slab area to avoid double counting.
This calculator takes 4 inputs: Slab soffit area, Total beam length, Beam depth below slab, Column formwork area. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.