Concrete Column Calculator
Work out how much concrete you need for round columns, piers, or tube forms (like Sonotube). Enter the diameter, height, and number of columns to get the volume and bag count.
Concrete column calculator
For round tube forms (like Sonotube), piers, and columns. An 80 lb bag of concrete mix yields about 0.6 ft³ and a 60 lb bag about 0.45 ft³.
How it's calculated
We compute the volume of each round column as pi × (diameter ÷ 2)² × height, multiply by the number of columns, then convert to cubic yards and to 60 lb and 80 lb bags, rounding up.
Frequently asked questions
- How much concrete for a column?
- The volume of a round column is pi times the radius squared times the height. Enter your tube diameter and height above for the cubic yards and bag count.
- How many bags of concrete for a Sonotube?
- A 12-inch tube 4 feet tall holds about 3.1 cubic feet — roughly 6 bags of 80 lb concrete mix. Use the calculator for your exact size.
- How deep should a concrete pier be?
- Footings usually extend below the frost line, which varies by region — check your local building code.
Last updated June 2026.