Concrete Column Calculator
Estimate concrete for round or square columns.
How It Works
Round: Volume (ft³) = π × (Diameter ÷ 2 ÷ 12)² × Height. Square: Volume = (Width ÷ 12)² × Height. × Number of Columns.
Example
A 12 in round column 10 ft tall: π × (0.5)² × 10 = 7.85 ft³ ≈ 0.29 cubic yards before waste.
Frequently Asked Questions
Round or square columns — does it matter?
Round columns use slightly less concrete for the same width, but square forms are easier to build and brace.
Should I add extra to columns?
Yes — 5–10% waste is smart for columns because of form fit, rebar, and spillage.
How many bags for a column?
Divide the column volume in cubic feet by the bag yield: 0.6 ft³ for an 80 lb bag.