Concrete Column Calculator
Volume and bags of concrete for round columns or tube footings.
Find the concrete needed to fill round columns, piers or cardboard tube forms (Sonotubes).
The math behind it
A column is a cylinder: volume = π × radius² × height. The diameter (inches) is halved and converted to feet.
Multiply by the number of columns and add waste; convert to cubic yards (÷27) or bags.
Worked example
One 12 in × 8 ft column → π × 0.5² × 8 = 6.28 ft³ (≈11 × 80 lb bags with waste).
FAQ
What is a Sonotube?
A waxed cardboard tube used as a one-time form to pour round concrete columns and footings.