ConcreteBag

How Many Bags of Concrete for a 18 Inch Sonotube?

⌀ 18 in4 ft (D)

A 18" tube filled 48" deep needs 13 bags of 80 lb concrete.

13bags

80 lb bags · estimated $90.74 at $6.98/bag

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Estimated cost: ~$90.74 (13 × $6.98/bag, Spring 2026 pricing)

Bag size

Multi-bag comparison

Bag sizeBagsPrice/bagTotal
80 lbBest value13$6.98$90.74
60 lb18$5.98$107.64
40 lb26$4.98$129.48

Prices are spring 2026 estimates. Above ~60 bags, price a ready-mix truck too — it is often cheaper.

Material list

  • 13 × 80 lb concrete mix bags $90.74 @ $6.98/bag (Spring 2026)Home Depot ↗Lowe's ↗
  • Wheelbarrow or mixing tub
  • Mixing hoe or drill paddle
  • Margin trowel or float
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13 bags(80 lb)
$90.74
Buy at Home Depot

How this is calculated

We convert your dimensions to cubic feet, add a 10% waste buffer for spillage and an uneven subgrade, then divide by the bag's yield and round up to the next full bag.

FAQ

How many bags of concrete for a 18 inch sonotube?

A 18-inch tube filled 48 inches deep needs about 13 bags of 80 lb or 18 bags of 60 lb concrete, including 10% waste.

How do I calculate concrete for a deeper or shallower tube?

Enter your depth in the calculator above and the bag count updates instantly. Concrete scales directly with depth.

How much concrete does a 18 inch sonotube hold?

About 7.1 cubic feet per 48 inches of depth for a 18-inch tube.