Basic
Round Column Calculator
Calculate concrete volume for round columns, pillars, and sonotubes. This calculator is perfect for deck support columns, porch pillars, fence posts, and any cylindrical concrete structure. Simply enter the diameter and height to get accurate results.
Enter Your Measurements
Formula Used
Volume (cu ft) = π × (Diameter ÷ 2)² × Height × Quantity Volume (cu yd) = Volume (cu ft) ÷ 27
Pro Tips
- •Sonotubes come in standard diameters: 6", 8", 10", 12", 14", 16"
- •Use a concrete vibrator to eliminate air pockets
- •For structural columns, consult an engineer for reinforcement requirements
- •Consider adding a footing below for proper load distribution
Frequently Asked Questions
What size sonotube do I need for a deck post?
For most deck posts, a 12-inch diameter sonotube is sufficient. For larger decks or heavy loads, use 14-16 inch diameters.
How long does concrete take to cure in a sonotube?
Concrete reaches about 70% of its strength in 7 days. Wait at least 24-48 hours before removing the sonotube form.