Calculate sonotube concrete volume, footing concrete quantity, and concrete bags needed using accurate contractor-grade concrete pier formulas.
Deck footing — 12 in Ø · 48 in depth · 6 tubes typical
| Diameter | Typical Use | Notes |
|---|---|---|
| 8 in | Fence posts, light decks | Check lateral load |
| 10–12 in | Deck footings, pergolas | Common residential choice |
| 14–16 in | Heavy decks, corners | Engineered plans may specify |
| 18–24 in | Pole barns, large piers | Higher volume per hole |
6× 12 in tubes, 48 in deep.
4× 8 in tubes, 36 in deep.
4× 10 in tubes, 42 in deep.
8× 18 in tubes, 48 in deep.
This sonotube calculator is a focused concrete pier calculator for cylindrical forms. For flatwork, use the concrete slab calculator or concrete volume calculator column mode.
Yes. Sonotube is a brand name for fiber forms; contractors often say concrete tube or pier form for the same cylindrical footing.
Eight 12-inch tubes at 4 feet deep total about 1.0 cubic yard net. With 8% waste, plan roughly 1.1 yards or about 50 bags of 80 lb mix.
Some crews pour into augered holes without forms. Volume math is the same cylinder; tubes keep the pier neat and sized.