Nine footings is a common layout for a small deck. Enter your own count and depth.
How it works
Volume = π × (diameter ÷ 2)² × height. Bags = volume ÷ bag yield, rounded up.
Example: a 10 in tube 3 ft tall holds 1.64 ft³, which is 3 bags of 80 lb concrete; 9 tubes take 25 bags.
At a glance
Same settings as the calculator above, changing only the tubes.
| Tubes | Concrete | Bags |
|---|---|---|
| 4 | 6.54 ft³ | 11 |
| 6 | 9.82 ft³ | 17 |
| 9 | 14.73 ft³ | 25 |
| 12 | 19.63 ft³ | 33 |
| 16 | 26.18 ft³ | 44 |
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.
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