How to use it
- Enter the tube diameter in inches.
- Enter the tube length in feet.
- Click Calculate to see the required 80‑lb bags.
Enter the diameter and length of your Sonotube and the calculator instantly tells you how many 80‑lb bags of concrete are required. It uses the industry‑standard that each 80‑lb bag yields about 0.6 ft³ of mixed concrete, then converts the cylindrical volume of the tube to cubic feet. Knowing the exact bag count helps you order the right amount, avoid costly over‑orders, and keep your project on schedule. The result is shown as a whole‑bag number; you’ll typically round up to ensure you have enough mix for the entire pour. No manual math, no guesswork – just a quick, reliable number you can trust before you call the supplier. You can also adjust the dimensions to compare different tube sizes or plan for multiple pours in the same job. The tool works on any device, so you can check the numbers on the job site or from the office.
Pro tips
- Add 5‑10% extra for spillage and settling.
- Always round up to the next whole bag.
- Order bags in multiples of 5 to reduce shipping fees.
- Measure the inside diameter of the tube, not the outer wall.
Real-life examples
- A homeowner pouring a 12‑in diameter, 8‑ft deep footing.
- A contractor estimating concrete for multiple 10‑in Sonotubes on a new patio.
- A landscape designer planning a raised garden bed with 6‑in tubes.
Case study
Mike needed concrete for a 12‑in, 6‑ft Sonotube. The calculator showed 11 bags; he ordered 12, saved a trip for extra mix, and finished on schedule.