How to use it
- Enter the tube diameter in inches.
- Enter the depth in feet.
- Enter the number of tubes you plan to install.
- Read cubic feet, cubic yards and 80‑lb bag count instantly.
What it does – The calculator takes the Sonotube diameter, the depth you plan to pour, and the number of columns, then instantly returns three practical measures: total cubic feet, cubic yards (the standard ordering unit), and the number of 80‑lb bags needed.
Why it matters – Ordering too little concrete delays the project and adds labor costs; ordering too much wastes money and creates excess material. Knowing the exact volume lets you budget accurately and schedule deliveries with confidence.
How to read the results – Cubic feet is the raw volume of the holes. One cubic yard equals 27 cubic feet, so divide the cubic‑feet total by 27 to see cubic yards. Each 80‑lb bag yields about 0.6 cubic feet, so divide the cubic‑feet total by 0.6 to get the bag count.
Pro tips
- Add a small waste allowance (5‑10%) for spillage and uneven depth.
- Round the bag count up to the next whole bag—you can’t order a fraction.
- Order bags in full pallets when possible to lower shipping costs.
- Verify that diameter is entered in inches and depth in feet before calculating.
Real-life examples
- Homeowner building 12‑in. fence post foundations.
- Contractor installing a row of 12‑in. concrete piers for a deck.
- Landscaper setting 12‑in. tree planting tubes in a garden.
Case study
Mike needed 8 Sonotube footings for his new deck. He entered 12 in., 4 ft depth and 8 units; the tool showed 6.4 cubic yards and 378 bags. He ordered exactly that amount, avoided a costly reorder, and finished on schedule.