How the Column and Pier Estimate Works
A round column uses π × radius² × height. A square column uses width × width × height. The calculator multiplies that volume by the number of identical columns, then applies the allowance you select.
For a 300mm diameter round column 1m high, the geometric volume is π × 0.15² × 1 = approximately 0.0707m³. With 10% selected, the planning quantity becomes approximately 0.0778m³.
Calculate different sizes separately
The count field assumes identical dimensions. If column diameters, widths or heights vary, calculate each size as a separate group and add the cubic-metre results.
Quantity is not structural design
The calculator does not determine column dimensions, reinforcement, concrete strength, footing connections or load capacity. Columns and piers can be structural elements, so use dimensions and specifications from approved plans or an appropriately qualified professional.
See the complete methodology and source list.