🧱Concrete Calculator

Calculate the volume of concrete needed for a slab and an estimate of ready-mix bags required.

Slab dimensions.

Length (m)

Width (m)

Thickness (cm)

Number of slabs

Concrete Volume

— m³

—

Cubic feet

—

Weight (kg)

—

40 kg ready-mix bags (approx)

About the Concrete Calculator

Volume is length × width × thickness. The bag estimate assumes each 40 kg bag of ready-mix concrete yields about 0.018 m³ — always buy a little extra to allow for spillage and uneven ground. Concrete weight assumes a density of about 2,400 kg/m³.