Carpenter

Concrete Quantities

Slab or footing volume and premix bags.

Length(m)

Width(m)

Depth(mm)

Wastage(%)

Concrete volume

0.945 m3

Volume (no wastage)0.9 m3

20 kg premix bags97

Formula

volume = L x W x (depth / 1000), then add wastage

3 x 3 x (100 / 1000) x 1.05 = 0.945 m3

For volumes over about 0.5 m3, ordering pre-mixed delivery is usually cheaper than bags.