Concrete calculator: how much concrete do I need?
Multiply length × width × depth, all in metres, to get the volume in cubic metres. Add about 10% for uneven ground and spillage.
Example: A base 3 m × 3 m and 100 mm deep is 3 × 3 × 0.1 = 0.9 m³, or about 0.99 m³ with 10% extra.
How to use it
- Measure the length and width of the area
- Decide the depth in millimetres with your builder
- Add the result to your list
- Allan can price it as ready-mix or as ballast and cement
These are estimates for planning and pricing, not specifications. Check quantities against your drawings, and follow your builder, engineer or the manufacturer’s guidance. Allan will check the quantities with you before anything is ordered.
Common questions
Should I order ready-mix or ballast and cement?
Ready-mix suits larger pours where a truck can get close. Ballast and cement suit small jobs or awkward access. Allan can price either, so mention access when you send your list.
How deep should a concrete base be?
It depends on what it carries and the ground. Shed and garden room bases, paths and house foundations all differ. Your builder, the product manufacturer or building control will set the depth.
How much extra concrete should I allow?
About 10% covers uneven ground and spillage on most small pours. Ordering a little over is better than running short halfway through.
Get it priced
- Nothing added yet. Use a calculator and press "Add to my list".