The basic formula
Concrete volume is just length × width × thickness, with every dimension in metres. The answer comes out in cubic metres (m³):
Volume (m³) = Length (m) × Width (m) × Thickness (m)
The only thing to watch is units. Slab and footing thickness is usually given in millimetres, so convert it first — divide by 1000. A 150 mm slab is 0.15 m thick.
Worked examples
A floor slab 4 m long, 3 m wide and 150 mm thick:
4 × 3 × 0.15 = 1.8 m³
A column 230 × 230 mm and 3 m tall:
0.23 × 0.23 × 3 = 0.159 m³ — round up to about 0.16 m³ each
For repeated elements — say ten identical columns — work out one and multiply by the count. For footings, calculate one footing and multiply by the number of footings.
Always add a wastage allowance
Real pours never use the exact theoretical volume. Spillage, uneven sub-grade, formwork bulge, and pump priming all consume a little extra. Add a wastage allowance on top of your calculated figure:
- Flat slabs and large pours: about 3–5%
- Columns, beams, and footings with rough ground: about 5–8%
- Small or awkward pours: up to 10%
For the 1.8 m³ slab above, a 5% allowance takes the order to roughly 1.9 m³.
Converting to transit-mixer loads
Our transit mixers carry up to 6 m³ each. Dividing your order quantity by 6 tells you roughly how many loads will arrive — useful for planning access, labour, and pour sequence.
1.9 m³ ÷ 6 ≈ 1 transit-mixer load
Larger pours that need several loads back-to-back are worth scheduling with us in advance so dispatch from the Mallavarappadu and Gundlapalli plants is continuous and the concrete stays workable.
Skip the maths — use the calculator
Our free concrete calculator does all of this for you. Pick the element type, enter the dimensions, set a wastage percentage, and it returns the order quantity in m³, the number of mixer loads, and a suggested grade. Send that figure to us as a starting point — our engineer confirms the volume, pumping, and site access on a free site visit before issuing your quote.