How to use it
- Enter the tube diameter in inches.
- Enter the depth in feet.
- Enter how many tubes you need.
- Read the cubic yards, bags and cubic feet results.
The Bigfoot Sonotube Concrete Calculator lets you instantly see how many cubic yards of concrete, how many 80‑lb bags, and the total cubic feet you’ll need for any Sonotube project. Knowing the exact volume prevents over‑ordering, saves money, and keeps your job on schedule. Just input the tube’s diameter, the depth you’ll pour, and the quantity of tubes. The tool converts the dimensions to cubic yards (the unit most suppliers use) and then to 80‑lb bags using the standard 0.6 ft³ per bag. Use the cubic‑feet figure for site‑level planning or when comparing mixed‑in‑place vs. bagged concrete. The results update instantly, so you can tweak dimensions and see the impact in real time. You can also multiply the single‑tube result by the quantity you entered to get the total material list for the whole job.
Pro tips
- Add 5‑10% extra for spillage and settling.
- Round up bag count to the next whole bag.
- Order bags in multiples of 5 for better pricing.
- Double‑check diameter units; 12 in tube ≈ 1 ft radius.
Real-life examples
- A homeowner building a 3‑ft deep patio footings with 12‑in Sonotubes.
- A contractor estimating concrete for 20 fence post footings.
- A landscaper planning a raised garden bed using 8‑in Sonotubes.
Case study
Mike needed 20 12‑in Sonotubes 4 ft deep for his new deck. Using the calculator he saw he required 2.4 cubic yards, which translates to 4 bags (0.6 ft³ each). He ordered exactly 4 bags, saved $30 on excess material, and finished on schedule.