Concrete for a 26×26 slab
8.35 cubic yards (414 × 80 lb bags)
for a 26×26 ft slab 4 inches thick: 225.3 cu ft. Bag counts include 10% extra; at 6 inches you need 12.52 yards.
A 26×26 foot slab covers 676 square feet. At the standard 4 inch thickness for a patio, walkway or shed floor, that is 225.3 cubic feet of concrete, or 8.35 cubic yards. At this size ready-mix is cheaper and far less work than bags: about 9.25 yards, roughly $1,526 before delivery fees, against $2,691 for 414 bags of 80 lb mix.
Concrete for a 26×26 slab by thickness
| Thickness | Cubic yards | Cubic feet | 80 lb bags | 60 lb bags | 40 lb bags |
|---|---|---|---|---|---|
| 3 in | 6.26 | 169 | 310 | 414 | 620 |
| 4 in | 8.35 | 225.3 | 414 | 551 | 827 |
| 5 in | 10.43 | 281.7 | 517 | 689 | 1033 |
| 6 in | 12.52 | 338 | 620 | 827 | 1240 |
| 8 in | 16.69 | 450.7 | 827 | 1102 | 1653 |
Bag counts include 10% extra for spillage and uneven ground. Cubic yards and cubic feet are the exact volume.
How it’s worked out
- Convert the thickness to feet: 4 in ÷ 12 = 0.333 ft.
- Multiply length × width × thickness: 26 × 26 × 0.333 = 225.33 cu ft.
- Divide by 27 for cubic yards: 225.33 ÷ 27 = 8.346 cu yd.
- Add 10% and divide by the bag yield: 247.87 ÷ 0.6 = 414 bags of 80 lb mix (rounded up).
Under the slab, plan on 4 inches of compacted gravel: about 8.35 cubic yards. For driveways and anything that carries a vehicle, go to 5 or 6 inches and add rebar or wire mesh.
Change the numbers
Other slab sizes
- 25×26 slab
- 24×26 slab
- 26×28 slab
- 22×26 slab
- 26×30 slab
- 20×26 slab
- 26×32 slab
- 18×26 slab
- 16×26 slab
- 26×36 slab
- 15×26 slab
- 14×26 slab
Questions
- How many bags of concrete do I need for a 26×26 slab?
- At 4 inches thick, a 26×26 slab takes 414 bags of 80 lb concrete mix, 551 bags of 60 lb mix or 827 bags of 40 lb mix, including 10% extra.
- How many yards of concrete for a 26×26 slab?
- 8.35 cubic yards at 4 inches thick, 10.43 at 5 inches and 12.52 at 6 inches, before adding extra for waste.
- How much does a 26×26 concrete slab cost?
- The concrete alone for a 4 inch 26×26 slab costs about $2,691 in 414 bags of 80 lb mix (at about $7 a bag) or about $1,526 for 9.25 yards of ready-mix (at about $165 a yard, before delivery fees). Professionally poured slabs usually run $6 to $12 per square foot, about $4,056 to $8,112 for 676 sq ft.
- How much does a 26×26 slab weigh?
- About 16.3 tons at 4 inches thick (concrete weighs about 145 lb per cubic foot).