Sonotube Concrete Calculator
Result
Volume per Tube 3.142 cu ft
Total Volume 12.566 cu ft
60 lb Bags Needed 28
80 lb Bags Needed 21
Calculate the volume of concrete needed to fill a cylindrical sonotube form.
Formula
V = π × r² × depth; 60 lb bag ≈ 0.45 cu ft; 80 lb bag ≈ 0.60 cu ft
- Common Sonotube diameters: 8, 10, 12, 14, 16 in.
- Depth should be below frost line (varies by region: 12–72 in).
- Add 10% to account for irregular holes and spillage.
12 in diameter, 48 in deep, 4 tubes
Inputs
- Sonotube Diameter: 12 in
- Depth: 48 in
- Number of Tubes: 4 tubes
Per tube: π × (0.5)² × 4 = 3.14 cu ft. 4 tubes = 12.57 cu ft → 28 bags (60 lb).
Frequently asked questions
What strength concrete for deck footings?
Use minimum 3,500 psi concrete for footings in cold climates. Quikrete 5000 or equivalent. Consider fiber-reinforced mix for crack resistance.