Basic
Sonotube Calculator
Calculate concrete for sonotubes and concrete tubes. Sonotubes are cylindrical cardboard forms used to create round concrete columns for decks, porches, and structural supports.
Enter Your Measurements
Formula Used
Volume (cu ft) = π × (Diameter ÷ 24)² × Height × Quantity Volume (cu yd) = Volume (cu ft) ÷ 27
Pro Tips
- •Sonotubes can be cut to length with a handsaw
- •Brace sonotubes securely before pouring
- •Fill with concrete in lifts, vibrating each layer
- •Leave the sonotube in place - it will decompose over time
Frequently Asked Questions
How many bags of concrete do I need for a 12" sonotube?
A 12-inch diameter sonotube, 4 feet tall, requires about 13 bags of 60lb concrete mix.
Should I remove the sonotube after pouring?
No, sonotubes are designed to remain in place. They will eventually decompose. You can peel off the outer layer if desired for aesthetic reasons.