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Concrete calculator

Enter the length, width and thickness. You see the concrete volume and the approximate materials to mix it.

Materials depend on the mix design. This calculator uses a general-purpose 1:2:3 mix as a reference.

How it's calculated

Volume = length × width × thickness, with the thickness in metres.
It adds the margin for uneven ground and spillage.
Per m³: about 350 kg of cement, 0.55 m³ of sand, 0.8 m³ of gravel and 180 litres of water.

An example

A 4 × 3 m slab, 10 cm thick, needs 1.2 m³ of concrete.

With the reference mix, that is about 420 kg of cement, 0.66 m³ of sand and 0.96 m³ of gravel.

Frequently asked questions

How many cubic feet are in a cubic yard?

27. A cubic yard is 3 ft × 3 ft × 3 ft. Ready-mix concrete is usually sold by the cubic yard.

How much cement is in a cubic metre of concrete?

With a 1:2:3 mix, about 350 kg. Stronger concrete uses more cement.

Should I order ready-mix?

For large pours it is usually more consistent and faster. For small jobs, mixing on site with these amounts is common.

Key terms

Mix design: The ratio of cement, sand, gravel and water in a mix.
Cubic yard (yd³): The volume of a cube 1 yard on each side: 27 cubic feet.

The same calculation in other countries

Up-to-date official data

We check the official sources automatically, every day.

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