Concrete Calculator
Pick the element type — slab, foundation or shear wall — and the area; see a rough required concrete volume (m³) based on a common reference thickness, plus an order suggestion with a 5% waste allowance.
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Let's determine your actual concrete class and volume together based on your structural calculation and soil surveyThis is a rough illustration using a common reference thickness for the selected element type; the actual thickness and concrete class (C25, C30, etc.) are determined by the engineer based on your structural calculation and soil survey.
How is concrete volume calculated?
Concrete volume is simply the area of the element to be poured multiplied by its thickness (Volume = Area × Thickness). On a real site, though, losses from transport, pumping and surface irregularities mean orders are usually placed with an extra 5-10% waste allowance on top of the calculated volume.
The tool above shows a rough concrete volume based on the common thickness for your selected element type and the area you enter, plus an order suggestion with a 5% waste allowance added on top.
Typical thickness by element type
Slabs (reinforced concrete floor plates between stories) are usually poured at 12-15 cm; raft/foundation concrete can reach 30 cm or more depending on soil bearing capacity and building load; shear/reinforced concrete walls are commonly 20-25 cm thick.
This tool uses a common reference thickness for each element type — your project's structural calculation and soil survey results may call for a different thickness.
Why a waste allowance is added
Formwork leakage, ground irregularities, residue left in the pump/mixer, and transport losses mean real consumption ends up somewhat above the calculated net volume. Common site practice is to add 5-10% on top of the calculated volume; this tool uses 5%.
Let's determine your actual concrete class and volume together based on your project's structural calculation and soil survey.
Contact usFrequently Asked Questions
How is concrete volume calculated?
Simple formula: Volume (m³) = Area (m²) × Thickness (m). For example, a 50 m² slab poured at 15 cm (0.15 m) thickness needs 50 × 0.15 = 7.5 m³.
Why is a waste allowance added to a concrete order?
Formwork leakage, ground irregularities, pump/mixer residue and transport losses mean real consumption ends up above the calculated net volume; common site practice is to add 5-10% on top.
What are typical thicknesses for a slab, foundation and shear wall?
Slabs are usually 12-15 cm, raft/foundation concrete is 30 cm or more depending on soil, and shear/reinforced concrete walls are commonly 20-25 cm. The exact value depends on your project's structural calculation.
Does this tool also calculate the concrete class (C25, C30, etc.)?
No. The tool only calculates volume (m³); concrete class/strength is a separate technical decision made by the engineer based on the soil survey and structural project.