About Concrete Calculator
The volume of material for a rectangular slab, bed, or trench is length × width × depth. This calculator uses volume in m³ = length in m × width in m × thickness in cm ÷ 100, then adds your waste allowance as a percentage. Weight = volume × density, and cost = volume × price per m³. The default density of 2,400 kg/m³ is for concrete; change it for gravel, mulch, or soil.
Also known as: Gravel Calculator, Mulch Calculator, Excavation Calculator.
How to use Concrete Calculator
- Fill in "Length", "Width", "Thickness or depth" and "Waste allowance", and the other options.
- The result appears below and updates as you type.
- Copy the result with the copy button, or download it as a file where that is offered.
Questions about Concrete Calculator
How much extra material should I order?
An allowance of 5% to 10% is common to cover uneven ground, spillage, and compaction. The default here is 5%. For loose fill that settles, such as gravel or mulch, a higher allowance is sensible.
How do I convert cubic metres to cubic yards?
Multiply cubic metres by 1.308. One cubic metre is about 1.308 cubic yards, or 35.3 cubic feet. Suppliers in the United States usually sell concrete and bulk materials by the cubic yard.
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