HisabCalc › Country-specific

Shuttering Area Calculator

Works out the formwork contact area for a slab, beam or column from its dimensions, and multiplies by the number of identical elements.

Enter your numbers

Element type

Length or span (m)

Example: 6.5

Width or breadth (m)

Example: 0.3

Depth or height (m)

Example: 0.6

Number of elements

Example: 8

Result

Currency

Figures are computed on your device; nothing is sent anywhere.

Formula

slab: area = length * width; beam: area = length * (2 * depth + width); column: area = 2 * (length + width) * depth; totalArea = area * count

How the calculation works

Shuttering is measured on the surfaces that touch wet concrete, so the shape of the element decides which faces are counted rather than the volume it holds.

A slab only has a soffit, a beam adds two side faces to that soffit, and a column is wrapped on all four sides, which is why the same dimensions give very different areas.

Multiplying the per-element area by the count gives the total plywood or steel sheet needed, and the estimator then adds a waste allowance on top.

Common mistakes

Using length times width for a beam ignores the two side faces and undercounts the shuttering by roughly half for a typical deep beam.
Adding a waste or overlap allowance before the count is multiplied in double counts it, since the allowance should apply only to the final total.

When to use it

Use it when ordering plywood, steel sheets or props, since the quantity you buy is driven by the contact area rather than the concrete volume.
Use it to compare a slab and a beam option for the same span, because a beam adds side faces and raises the shuttering needed per metre.

Worked example

For a beam 6.5 m long, 0.3 m wide and 0.6 m deep, one beam needs 6.5 times 1.5, or 9.75 square metres of shuttering, and eight beams need 78 square metres.

Shuttering area per element (sq m) 9.75

Total shuttering area (sq m) 78.00

Common questions

How is shuttering area counted for a beam compared with a slab?

A slab uses only the soffit, so area is length times width, while a beam also needs both side faces, so its area is length times two times depth plus width.

Last updated: 2026-10-04