🧱 Concrete Calculator
Cubic yards for slabs and footings
About this calculator
Concrete is ordered by the cubic yard (or cubic metre), not by guesswork. Enter the length, width, and thickness of your slab, footing, or column, and the calculator computes the volume in cubic yards and cubic metres, plus how many bags of premix you'd need as an alternative. It adds a standard 5–10% waste factor for spillage and uneven ground.
Tip: for anything over about half a cubic metre, ordering ready-mix from a truck is usually cheaper and far easier than mixing dozens of bags yourself.