How to use it
- Enter the tube diameter in inches.
- Enter the tube depth in feet.
- Enter the quantity of tubes you need.
- Read the cubic yards, cubic feet and bag count results.
What it does – The calculator takes the diameter (inches), depth (feet) and how many 8‑in. Sonotube columns you need, then instantly tells you the total concrete volume in cubic yards, cubic feet, and the number of standard 80‑lb bags required.
Why it matters – Knowing the exact bag count prevents over‑ordering, saves money, and ensures you have enough mix on site to avoid project delays.
How to read the results – The cubic‑feet figure is the raw volume of all tubes combined. Divide that by 27 to see cubic yards, the unit most suppliers quote. Divide cubic feet by 0.6 to get the bag count; always round up to the next whole bag. You can also adjust for waste by adding 5‑10 % to the bag total. The tool works for any number of tubes, from a single footing to a full fence line, and works on desktop or mobile browsers.
Pro tips
- Add 5‑10 % extra for waste to avoid shortfalls
- Round the bag total up to the next whole bag
- Order a few extra bags in case of spillage or mis‑measurements
- Double‑check diameter and depth units before calculating
Real-life examples
- A homeowner estimating concrete for a new deck footings
- A contractor pricing material for a fence post line
- A landscaper planning a garden retaining wall with multiple columns
Case study
Mike needed 4 bags for three 8‑in. Sonotubes, each 2 ft deep. The calculator showed 0.08 yd³ total, 2.1 ft³, and 4 bags after rounding, so he ordered exactly what he used, avoiding a costly over‑order.