Concrete for a 24×24 slab
7.11 cubic yards (352 × 80 lb bags)
for a 24×24 ft slab 4 inches thick: 192 cu ft. Bag counts include 10% extra; at 6 inches you need 10.67 yards.
A 24×24 foot slab covers 576 square feet. At the standard 4 inch thickness for a patio, walkway or shed floor, that is 192 cubic feet of concrete, or 7.11 cubic yards. At this size ready-mix is cheaper and far less work than bags: about 8 yards, roughly $1,320 before delivery fees, against $2,288 for 352 bags of 80 lb mix.
Concrete for a 24×24 slab by thickness
| Thickness | Cubic yards | Cubic feet | 80 lb bags | 60 lb bags | 40 lb bags |
|---|---|---|---|---|---|
| 3 in | 5.33 | 144 | 264 | 352 | 528 |
| 4 in | 7.11 | 192 | 352 | 470 | 704 |
| 5 in | 8.89 | 240 | 440 | 587 | 880 |
| 6 in | 10.67 | 288 | 528 | 704 | 1056 |
| 8 in | 14.22 | 384 | 704 | 939 | 1408 |
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: 24 × 24 × 0.333 = 192 cu ft.
- Divide by 27 for cubic yards: 192 ÷ 27 = 7.111 cu yd.
- Add 10% and divide by the bag yield: 211.2 ÷ 0.6 = 352 bags of 80 lb mix (rounded up).
Under the slab, plan on 4 inches of compacted gravel: about 7.11 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
- 24×25 slab
- 22×24 slab
- 24×26 slab
- 20×24 slab
- 24×28 slab
- 18×24 slab
- 24×30 slab
- 16×24 slab
- 24×32 slab
- 15×24 slab
- 14×24 slab
- 12×24 slab
Questions
- How many bags of concrete do I need for a 24×24 slab?
- At 4 inches thick, a 24×24 slab takes 352 bags of 80 lb concrete mix, 470 bags of 60 lb mix or 704 bags of 40 lb mix, including 10% extra.
- How many yards of concrete for a 24×24 slab?
- 7.11 cubic yards at 4 inches thick, 8.89 at 5 inches and 10.67 at 6 inches, before adding extra for waste.
- How much does a 24×24 concrete slab cost?
- The concrete alone for a 4 inch 24×24 slab costs about $2,288 in 352 bags of 80 lb mix (at about $7 a bag) or about $1,320 for 8 yards of ready-mix (at about $165 a yard, before delivery fees). Professionally poured slabs usually run $6 to $12 per square foot, about $3,456 to $6,912 for 576 sq ft.
- How much does a 24×24 slab weigh?
- About 13.9 tons at 4 inches thick (concrete weighs about 145 lb per cubic foot).