10 Inch Sonotube Calculator — Concrete Per Footing
Calculate concrete volume and bag count for 10-inch diameter Sonotube footings — the most common size for residential deck and porch posts at any depth.
Enter Dimensions
Depth below grade to bottom of footing
Results
Bags per Tube
5bags
Total Bags
20bags
Volume per Tube
2.18cu ft
Concrete volume for one tube
Total Volume
0.323cu yd
All tubes combined
Editorial Standards
Each calculator is reviewed for formula accuracy, unit consistency, and alignment with current U.S. building practices before publication. We verify outputs against published engineering references and real-world project data. Learn more about our methodology.
10-inch Sonotube is the workhorse residential deck and porch footing — large enough to handle realistic snow and live loads on typical 6 ft × 14 ft deck bays, small enough to dig with a manual auger or post-hole digger. It's the default in IRC Table R507.3 for most code-compliant residential deck construction.
This calculator returns the per-footing concrete volume in cubic feet and converts to 60-lb and 80-lb bag counts. Use it before you head to the supplier so you know exactly how much material to order.
How to Pour a 10 Inch Sonotube Footing
Volume = π × (10 ÷ 24)² × Depth (ft) × 12 = 0.545 cu ft per foot of depth.
10″ Sonotube Bag Reference
- 2 ft deep: 1.09 cu ft ≈ 2 bags 80 lb
- 3 ft deep: 1.64 cu ft ≈ 3 bags 80 lb
- 4 ft deep: 2.18 cu ft ≈ 4 bags 80 lb
- 5 ft deep: 2.73 cu ft ≈ 5 bags 80 lb
- 6 ft deep: 3.27 cu ft ≈ 6 bags 80 lb
Deck projects typically have 4–10 footings. Above 6–8 footings at 4 ft+ depth, the math usually favors a short-load ready-mix delivery over bag mixing.
Frequently Asked Questions
How much concrete fills a 10 inch sonotube?
Volume per foot of depth: π × (5/12)² = 0.545 cu ft/ft. A 4 ft footing = 2.18 cu ft (~4 bags 80 lb); a 5 ft footing = 2.73 cu ft (~5 bags 80 lb).
Is a 10 inch sonotube big enough for a deck post?
Yes — 10″ is the most common deck footing size and is sized per IRC Table R507.3 for tributary loads up to about 80 sq ft in moderate snow zones. Heavier loads or larger spans warrant 12″ piers.
How deep should a 10 inch sonotube go for a deck?
Below the local frost line — typically 36–48 inches in the U.S. northern tier and 12–24 inches in southern states. Always confirm with the local building department.
Do I need rebar in a 10 inch sonotube?
A single vertical #4 bar through the center is the residential minimum for a single-tube deck post. A 4-bar tied cage is required for piers under load-bearing beams or attached structures.
How many bags of concrete for ten 10 inch piers, 4 ft deep?
10 × 2.18 cu ft = 21.8 cu ft total. At 0.60 cu ft per 80 lb bag, that's 37 bags — or about 0.8 cubic yards if you order ready-mix.
Looking for the general calculator?
Calculate concrete volume and bags needed to fill Sonotube forms for deck posts and piers. Supports 6, 8, 10, and 12-inch diameter tubes at any footing depth.
Open the Sonotube Calculator: Bags Per Footing →