Concrete Calculator
Work out the volume of concrete a slab needs, in cubic metres or cubic yards, before you order from the plant.
Concrete calculators
Volume and mix quantities for poured concrete work. These are material estimates: the concrete grade and the structural design still come from your engineer or supplier.
What you can calculate here
- Slab volume from length, width and thickness.
- Volume converted to m³ or yd³ depending on your unit system.
- A waste allowance for spillage, uneven sub-base and over-dig.
Concrete calculators
Concrete questions
How much extra concrete should I order?
Order 5–10 % more than the calculated volume. Running short mid-pour is far more expensive than a small surplus.
Do I need to add water or cement to the estimate?
No. Ready-mix suppliers price by volume. Use the cement mortar calculator only when you are mixing on site.