How is concrete volume calculated for a slab?

Slab volume = Length × Width × Thickness. For example, a 5m × 4m × 0.15m slab = 3 m³ of concrete.

How many bags of cement per m³ for M20 concrete?

For M20 concrete (1:1.5:3 mix), approximately 8 bags of cement (50 kg each) are required per cubic metre of finished concrete.

What wastage factor should I use?

For regular work, a 5% wastage factor is standard. For areas with complex formwork or difficult access, use 8–10%.

Concrete Volume Calculator

Calculate concrete volume for slabs, beams, columns, and footings.

Element type

Length (m)

Width (m)

Depth / Thickness (m)

Wastage (%)

Net volume

3.000 m³

With wastage

3.150 m³

In litres

3150 L

Weight (≈)

7560 kg

M20 concrete material estimate (1:1.5:3 mix)

Cement

25.2 bags (50 kg)

Fine aggregate (sand)

1.323 m³

Coarse aggregate

2.646 m³

Volume = L × W × H = 5 × 4 × 0.15 = 3.0000 m³

Calculate concrete quantity for any element

Select the structural element, enter dimensions, and get exact concrete volume plus material quantities for cement, sand, and aggregate based on M20 mix design.

Frequently asked questions

How is concrete volume calculated for a slab?: Slab volume = Length × Width × Thickness. For example, a 5m × 4m × 0.15m slab = 3 m³ of concrete.
How many bags of cement per m³ for M20 concrete?: For M20 concrete (1:1.5:3 mix), approximately 8 bags of cement (50 kg each) are required per cubic metre of finished concrete.
What wastage factor should I use?: For regular work, a 5% wastage factor is standard. For areas with complex formwork or difficult access, use 8–10%.

Calculate concrete quantity for any element

Frequently asked questions

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