Concrete Volume Calculator

Calculate net concrete volume and order volume for slabs, footings, walls, beams or columns with metric and imperial dimensions.

Calculation parameters

Construction type

Length

Width

Thickness

Number of identical elements Extra allowance

0% by default. The calculator never adds an allowance automatically.

Result

Net volume

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Important

This tool estimates volume only from the dimensions you provide. It does not determine safe structural dimensions, reinforcement, concrete class/strength, or building-code compliance.

Rectangular construction: V = length × width × height/thicknessAll dimensions are converted exactly to metres before calculation.

Round columns and piers: V = π × (diameter ÷ 2)² × heightMath.PI is used without intermediate rounding.

How concrete volume is calculated

The calculator determines geometric volume from the dimensions you provide. Quantity multiplies the volume of one element, and the optional allowance is applied exactly once afterward.

For example, a 4 × 3 m slab that is 0.1 m thick:

4 × 3 × 0.1 = 1.2 m³

With a 10% allowance, the order volume is 1.32 m³.

Examples 4 × 3 × 0.1 m slab = 1.2 m³20 × 0.4 × 0.6 m strip footing = 4.8 m³8 × 2.5 × 0.2 m wall = 4.0 m³Ø0.3 m × 3 m round column ≈ 0.2121 m³

Does the calculator add a concrete allowance automatically?

No. The default allowance is 0%. Enter your own percentage only when it is appropriate for your project.

Can I mix metres, centimetres and millimetres in one calculation?

Yes. Each dimension can use its own unit. The calculator normalizes all values exactly before calculating volume.

Why does the calculator not show a number of concrete bags?

Bag weight alone does not determine finished concrete yield. A professional bag calculation requires the manufacturer-stated volume yield per bag.

How should I calculate an irregular or compound shape?

Split it into simple non-overlapping geometric parts, calculate each volume separately, and add the results.

Articles and explanations

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FOUNDATIONS, CONCRETE & MASONRY

How to Calculate Concrete Volume for Slabs, Footings, Walls and Columns Concrete volume is the amount of three-dimensional space that must be filled by concrete for a given shape. For a slab, strip footing, wall, beam or column, the calculation starts with the dimensions and geometry of the element rather than with bag count or concrete strength. In metric work the result is normally expressed in cubic metres (m³). Litres can be useful for smaller quantities, while imperial projects commonly use cubic feet (ft³) and cubic yards (yd³). The key requirement is that linear dimensions are converted to compatible units before they are multiplied. This guide explains net..

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