12 Inch Sonotube: How Much Concrete?
A 12 in Sonotube holds 0.79 cu ft of concrete per foot (π × r²). A 4 ft tube takes 3.1 cu ft: 6 bags of 80 lb or 7 bags of 60 lb Quikrete Concrete Mix. Sonoco's Builder's Tube chart says 0.80 cu ft per foot and about 1.3 bags of 80 lb mix per foot.
Concrete by tube length
| Tube length | Cu ft | Cu yd | 80 lb bags | 60 lb bags |
|---|---|---|---|---|
| 2 ft | 1.6 | 0.06 | 3 | 4 |
| 3 ft | 2.4 | 0.09 | 4 | 6 |
| 4 ft | 3.1 | 0.12 | 6 | 7 |
| 6 ft | 4.7 | 0.17 | 8 | 11 |
| 8 ft | 6.3 | 0.23 | 11 | 14 |
| 12 ft | 9.4 | 0.35 | 16 | 21 |
Your tubes
Set up for: 12 in sonotubes · Different project?
Other sizes: 6 in · 8 in · 10 in · 14 in · 16 in · 18 in · 24 in · all sizes
FAQ
How many bags of concrete for a 12 inch sonotube?
1.31 bags of 80 lb Quikrete Concrete Mix per foot of tube, so 6 whole bags for a 4 ft tube and 21 for four of them.
Is a 12 inch sonotube big enough for my deck?
We don't size footings. The diameter and depth come from your deck plans, an engineer or your local building department; this page turns that size into concrete.
Sources
- Sonoco: Sonotube Builder's Tube concrete forms (concrete chart) · fetched and reviewed 2026-11-10
- Sonoco: Sonotube Round concrete forms brochure (concrete requirements table) · fetched and reviewed 2026-11-10
- Quikrete: QUIKRETE Concrete Mix (No. 1101) data sheet · fetched and reviewed 2026-11-10
Volumes only. ConcreteMath calculates volumes, bag counts, weights and your own cost figures. It gives no structural or engineering advice and never sizes footings, piers, slabs or rebar: those come from your plans, an engineer or your local building department. Bag counts are estimates from each maker's published yield; actual use varies with hole shape, uneven ground, waste and mixing. Bulk weights are published ranges; your supplier's figure wins.