Concrete Calculator NZ

Work out how much concrete you need for a slab, strip footing, round pour or post holes. Includes waste allowance, recommended order quantity and approximate premix bag counts.

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1. Choose your pour

How the calculation works

The calculator converts your measurements to metres and calculates the geometric volume in cubic metres (m³). Your selected waste allowance is then added, and the ready-mix quantity is rounded up to your chosen increment.

Slabs: length × width × depth × quantity
Strip footings: length × width × depth × quantity
Round pours: π × radius² × depth × quantity
Post holes: π × radius² × depth × number of holes

Premix bag quantities are indicative only. The calculator assumes an approximate yield proportional to about 9 litres per 20 kg bag. Always use the yield printed on the product you are buying.

Put this calculator on your website

NZ builders, landscapers and concrete suppliers may embed this calculator free of charge.

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Calculator by TradeQuote

Olivergroup Software