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Sonotube Calculator
Work out concrete and bags for round form tubes.
Your result
Enter your numbers and press the button. Your result appears here.
Concrete form tubes are sold in diameters from 6 to 24 in and more. Volume = π × radius² × height.
How it works
Volume = π × (diameter ÷ 2)² × height. Bags = volume ÷ bag yield, rounded up.
Example: a 12 in tube 4 ft tall holds 3.14 ft³, which is 6 bags of 80 lb concrete.
At a glance
Same settings as the calculator above, changing only the height.
| Height | Concrete | Bags |
|---|---|---|
| 2 ft | 1.57 ft³ | 3 |
| 3 ft | 2.36 ft³ | 4 |
| 4 ft | 3.14 ft³ | 6 |
| 5 ft | 3.93 ft³ | 7 |
| 6 ft | 4.71 ft³ | 8 |
Bag yields
| Bag | Yield | Bags per yd³ |
|---|---|---|
| 40 lb | 0.30 ft³ | 90 |
| 50 lb | 0.375 ft³ | 72 |
| 60 lb | 0.45 ft³ | 60 |
| 80 lb | 0.60 ft³ | 45 |
Quikrete Concrete Mix product data.
All sonotubes calculators
Common questions
How much concrete does a 12 inch sonotube hold?
About 0.785 cubic feet per foot of height, so a 4 ft tube takes about 3.1 ft³, or 6 bags of 80 lb mix.
Which bag size should I use?
80 lb bags yield 0.60 ft³ and 60 lb bags 0.45 ft³, according to Quikrete. Fewer, heavier bags mean fewer trips but more lifting.
Sources
- Quikrete, Concrete Mix data sheet (bag yields): https://www.quikrete.com/PDFs/DATA_SHEET-Concrete%20Mix%201101.pdf