How many bags of concrete for a 10 inch Sonotube?
A 10 inch Sonotube 4 feet deep holds 2.18 cubic feet of concrete, so it takes 4 bags of 80 lb (3.8 bags exactly, with 5% extra) or 6 of 60 lb.
How to work it out
- 3.1416 × (10 in ÷ 2)² = 0.545 cu ft per foot × 4 ft = 2.18 cu ft
- + 5% = 2.29 cu ft ÷ 0.6 cu ft per 80 lb bag = 3.8 bags per tube
- One tube: buy 4 bags
A 10 in tube is about two-thirds the volume of a 12 in tube at the same depth, which is easy to forget when you are buying for a dozen of them. It is common under pergola and porch posts and some low decks.
Adjust for your project
More options: Extra
- Bags per tube
- 3.8 bags
- If you mix each tube separately, buy
- 4 bags · 80 lb bag
- Concrete per tube
- 2.29 cu ft (0.0848 cu yd)
- Or ready-mix, all tubes (incl. extra)
- 0.0848 cu yd (2.29 cu ft)
- Concrete per foot of tube
- 0.545 cu ft
- Weight of the concrete (≈ 145 lb/cu ft)
- 316 lb (0 tons)
- Total to buy counts this as bags. Switch “How will you buy it?” to ready-mix truck if you are ordering a delivery.
- Call 811 (in the US) or your local utility locate service a few days before you dig.
10 inch tube at other depths (5% extra)
| Concrete depth in the tube | Bags per tube | Bags of mix | Concrete per tube |
|---|---|---|---|
| 2 ft | 1.9 bags | 2 bags | 1.15 cu ft |
| 3 ft | 2.9 bags | 3 bags | 1.72 cu ft |
| 4 ft | 3.8 bags | 4 bags | 2.29 cu ft |
| 5 ft | 4.8 bags | 5 bags | 2.86 cu ft |
| 6 ft | 5.7 bags | 6 bags | 3.44 cu ft |
About one 80 lb bag per foot
At 0.545 cu ft per foot of depth, a 10 in tube takes very nearly one 80 lb bag per foot (0.91 bags) — Sonoco’s Builder’s Tube table rounds it to exactly 1 — or 1.2 bags of 60 lb. That makes the shopping list easy: count the total feet of tube and buy that many 80s, plus one or two spares.
Quikrete’s QUIK-TUBE table lists a 10 in tube 4 ft deep at 4 bags of 80 lb or 5 of 60 lb, before any extra. With 5% added, the 60 lb count tips over to 6, which is why the answer above says 6. If your holes are neat and the tube sits on firm, tamped ground, 5 may do it.
Ten inches or twelve?
Whether a 10 in pier is enough is a structural question for your plans and building department, based on the load and the soil. Going up to 12 in adds about 44% more concrete per tube; going down to 8 in saves about 36%. Compare the larger size on how many bags of concrete for a 12 inch Sonotube; a post set straight in a hole without a tube is on how much concrete for a 6×6 post.
Different size? Use the full Sonotube Calculator.
What you’ll need
- Cardboard concrete tube formBudget price
Round fiber tubes form piers, columns and footings above or below grade. Sold in common diameters; cut to length with a handsaw.
See options on Amazon (opens in a new tab) - Post hole diggerMid-range price
Digs neat, straight-sided holes. For more than a dozen holes, rent a powered auger and use this to clean them out.
See options on Amazon (opens in a new tab) - Post levelBudget price
Straps to a post or tube form and reads plumb in both directions at once, so you can set it while the concrete is still soft.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
How many bags of concrete for a 10 inch Sonotube 3 feet deep?
3 bags of 80 lb with 5% extra.
How many 60 lb bags for a 10 inch Sonotube?
6 bags of 60 lb for a 4 foot tube with 5% extra (5.1 bags exactly).
How many bags for six 10 inch Sonotubes 4 feet deep?
23 bags of 80 lb, sharing batches between tubes.
Other common sizes
- How many bags of concrete for a 12 inch Sonotube — 6 bags of 80 lb for a tube 4 ft deep
- How many bags of concrete for an 8 inch Sonotube — 4 bags of 60 lb for a tube 4 ft deep
Sources
- Sonoco — Sonotube round concrete forms brochure (opens in a new tab) — Diameters 6 to 36 in; standard length 12 ft; concrete requirements in cubic yards by diameter and height.
- Sonoco — Sonotube Builder’s Tube concrete forms (opens in a new tab) — 6, 8, 10 and 12 in diameters in 4, 8 and 12 ft lengths; about 0.20, 0.35, 0.55 and 0.80 cu ft per foot of height.
- Quikrete QUIK-TUBE (No. 6922) data sheet (opens in a new tab) — 4 ft lengths in 8, 10 and 12 in diameters; 10 and 12 ft regionally.
- Quikrete Concrete Mix (No. 1101) data sheet (opens in a new tab) — Yields: 40 lb ≈ 0.30, 50 lb ≈ 0.375, 60 lb ≈ 0.45, 80 lb ≈ 0.60, 90 lb ≈ 0.675 cu ft; unit weight ≈ 140 lb/cu ft; for pours 2 in thick or more; 6–9 pints of water per 80 lb bag; control joints every 6–8 ft; cure 5 days at 70 °F or above, 7 days at 50–70 °F; protect from freezing for 48 hours.
- 811 — Before You Dig (opens in a new tab) — The free national before-you-dig service; contact it a few business days before digging.