8″ Diameter 0.349 sq ft
8-Inch Sonotube & Pier Footing
Standard residential deck support piers (single-story decks) and fence corner and gate post footings.
Vol / Ft 0.349 cu ft
4ft Depth Yds 0.06 yd³
4ft 80lb Bags 3 bags
Sonotube Concrete Form Sizing & Pier Guides
Pouring cylindrical deck piers, post foundations, or commercial caissons? Select a standard tube diameter below to access verified concrete volume tables, bag calculations (80 lb & 60 lb), rebar cage specifications, and allowable soil bearing loads across standard frost-line depths.
Standard Sonotube Diameters
10″ Diameter 0.545 sq ft
10-Inch Sonotube & Pier Footing
Multi-level residential deck footings and sunroom foundations and carport, pergola, and outdoor pavilion column piers.
Vol / Ft 0.545 cu ft
4ft Depth Yds 0.09 yd³
4ft 80lb Bags 4 bags
12″ Diameter 0.785 sq ft
12-Inch Sonotube & Pier Footing
Heavy multi-story deck posts and elevated deck support columns and agricultural pole barn foundation piers (with uplift rebar ties).
Vol / Ft 0.785 cu ft
4ft Depth Yds 0.13 yd³
4ft 80lb Bags 6 bags
16″ Diameter 1.396 sq ft
16-Inch Sonotube & Pier Footing
Heavy structural building columns and commercial deck supports and industrial equipment pad footings and machinery mounts.
Vol / Ft 1.396 cu ft
4ft Depth Yds 0.23 yd³
4ft 80lb Bags 11 bags
18″ Diameter 1.767 sq ft
18-Inch Sonotube & Pier Footing
High-capacity commercial building columns and pole structures and highway and municipal overhead sign foundations.
Vol / Ft 1.767 cu ft
4ft Depth Yds 0.29 yd³
4ft 80lb Bags 13 bags
24″ Diameter 3.142 sq ft
24-Inch Sonotube & Pier Footing
Heavy commercial grade caissons and foundation columns and ground-mount solar array tracker foundation piers.
Vol / Ft 3.142 cu ft
4ft Depth Yds 0.51 yd³
4ft 80lb Bags 24 bags
Need Custom Hole or Post Hole Sizing?
If you are embedding square 4x4 or 6x6 timber posts into concrete holes or need non-standard excavation dimensions, use our dedicated Post Hole Calculator with automatic post volume displacement deduction.
Open Post Hole Calculator →