Formwork Area Calculator
Select element type (column, beam, slab), enter section size, length and count to compute the total timber formwork area for concrete works.
Input Data
Results
At a glance:Formwork (mould) area is the element's outer surface laid out: a column has four sides, single area = 2×(width + height)×length; a beam has two sides plus soffit, single area = (2×height + width)×length; a slab counts only the soffit, single area = width×length. Total formwork area = single area × count. Overlapping forms at joints are slightly reduced in practice; this calculator estimates independent elements.
Formula
Column: A = 2×(width+height)×length
Beam: A = (2×height+width)×length
Slab: A = width×length
Total area = A × count
$$A_{\text{col}} = 2(w+h)L$$$$A_{\text{beam}} = (2h+w)L$$$$A_{\text{slab}} = wL$$$$A_t = A \times n$$How to Use
- Select the element type (column/beam/slab).
- Enter the section width and height (slab: width and thickness).
- Enter the element length and count.
- The tool outputs total formwork area (m²).
Case Studies
Site beam form
0.3×0.5 m beam, 4 m long, 10 off.
Single = (2×0.5+0.3)×4 = 5.2 m²; 10 off = 52 m².
Structural column form
0.4×0.4 m column, 3 m high, 8 off.
Single = 2×(0.4+0.4)×3 = 4.8 m²; 8 off = 38.4 m².
FAQ
Why doesn't slab form count thickness?
Slab form only supports the soffit under the concrete; thickness does not affect the contact form area, so only width×length is counted.
Does beam-column joint double count?
This calculator estimates independent elements; overlapping forms at joints are slightly reduced in practice. Large projects may deduct 3–5% overlap by experience.
Is formwork area related to concrete volume?
They are independent: volume is about bulk, formwork about contact area. At the same volume, slender elements have larger formwork area.
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References
Content review: Calculatorism Construction Team. Results are for reference only; please refer to the relevant authorities for the official figures.