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Construction tool

Concrete Volume Calculator

Estimate concrete for slabs, footings, walls, columns or circular elements and add an explicit waste allowance.

Calculate concrete volume

Estimate concrete for slabs, footings, walls, columns or circular elements and add an explicit waste allowance.

Net volume—
Volume incl. waste—
Cubic yards—
Litres—

How the concrete volume calculator works

Rectangular volume is length × width × depth. Cylindrical volume is π × radius² × height. The element count multiplies net volume, and the waste percentage is applied afterward.

Where this construction calculation helps

Use it for slabs, strip footings, pads, walls, columns and other simple shapes before ordering ready-mix or estimating site batching.

Measurements and assumptions

Use finished internal dimensions in metres. Irregular excavations, slopes, rebates, embedded voids and uneven subgrade should be broken into smaller shapes or measured with a more detailed takeoff. Waste is project-specific.

Worked example

A 5 m × 4 m slab at 150 mm thick contains 3.0 m³ net concrete; adding 5% allowance gives 3.15 m³.

Before placing an order

Compare the calculated quantity with drawings, site measurements and supplier minimum loads. Openings, thickened edges, steps and irregular foundations may need separate calculations. Ready-mix orders are commonly placed in supplier-specific increments, so round only after confirming the delivery rules and the project's tolerance for leftover concrete.

Frequently asked questions

How do I convert slab thickness from mm to metres?
Divide millimetres by 1,000; for example, 150 mm is 0.15 m.
Should I always add 5% waste?
No. Use a project-specific allowance based on placement conditions, subgrade tolerance and supplier ordering increments.
Can it calculate round columns?
Yes. Select the cylinder option and enter diameter and height.
Does reinforcement reduce concrete volume?
Rebar displacement is usually small for preliminary concrete quantity estimates, but detailed project specifications should control final orders.