How to use the concrete column calculator
This calculator helps you measure round or rectangular columns and estimate a stated reinforcement allowance. It is intended for quantity takeoffs, early budgets and checks against a measured schedule. Start with the dimensions or quantities for one clearly defined item of work. Enter values in the units shown beside each field; millimetres and metres are not interchangeable.
Rebar is a user-defined weight allowance only, not a bar schedule or structural design. It cannot determine safe column dimensions, reinforcement arrangement or load capacity.
Worked example
A 300 mm diameter column, 3 m high, has a volume of about 0.212 m³. Multiply by the number of identical columns.
Before you order
Compare the result with your drawings and supplier information. Keep the original net quantity separate from allowances, and round purchasing quantities only at the ordering stage. Check whether delivery, labour and related materials belong elsewhere in your estimate. If the drawing or specification changes, update the inputs and record the revised basis instead of reusing an earlier total.
For the concepts behind this calculation, read Rebar (Reinforcement Steel), Concrete Grade, Formwork.