Concrete for a 24×32 slab
9.48 cubic yards (470 × 80 lb bags)
for a 24×32 ft slab 4 inches thick: 256 cu ft. Bag counts include 10% extra; at 6 inches you need 14.22 yards.
A 24×32 foot slab covers 768 square feet. At the standard 4 inch thickness for a patio, walkway or shed floor, that is 256 cubic feet of concrete, or 9.48 cubic yards. At this size ready-mix is cheaper and far less work than bags: about 10.5 yards, roughly $1,733 before delivery fees, against $3,055 for 470 bags of 80 lb mix.
Concrete for a 24×32 slab by thickness
| Thickness | Cubic yards | Cubic feet | 80 lb bags | 60 lb bags | 40 lb bags |
|---|---|---|---|---|---|
| 3 in | 7.11 | 192 | 352 | 470 | 704 |
| 4 in | 9.48 | 256 | 470 | 626 | 939 |
| 5 in | 11.85 | 320 | 587 | 783 | 1174 |
| 6 in | 14.22 | 384 | 704 | 939 | 1408 |
| 8 in | 18.96 | 512 | 939 | 1252 | 1878 |
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: 32 × 24 × 0.333 = 256 cu ft.
- Divide by 27 for cubic yards: 256 ÷ 27 = 9.481 cu yd.
- Add 10% and divide by the bag yield: 281.6 ÷ 0.6 = 470 bags of 80 lb mix (rounded up).
Under the slab, plan on 4 inches of compacted gravel: about 9.48 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
- 25×32 slab
- 24×30 slab
- 22×32 slab
- 26×32 slab
- 24×28 slab
- 24×36 slab
- 20×32 slab
- 28×32 slab
- 24×26 slab
- 24×25 slab
- 18×32 slab
- 24×24 slab
Questions
- How many bags of concrete do I need for a 24×32 slab?
- At 4 inches thick, a 24×32 slab takes 470 bags of 80 lb concrete mix, 626 bags of 60 lb mix or 939 bags of 40 lb mix, including 10% extra.
- How many yards of concrete for a 24×32 slab?
- 9.48 cubic yards at 4 inches thick, 11.85 at 5 inches and 14.22 at 6 inches, before adding extra for waste.
- How much does a 24×32 concrete slab cost?
- The concrete alone for a 4 inch 24×32 slab costs about $3,055 in 470 bags of 80 lb mix (at about $7 a bag) or about $1,733 for 10.5 yards of ready-mix (at about $165 a yard, before delivery fees). Professionally poured slabs usually run $6 to $12 per square foot, about $4,608 to $9,216 for 768 sq ft.
- How much does a 24×32 slab weigh?
- About 18.6 tons at 4 inches thick (concrete weighs about 145 lb per cubic foot).