Concrete for a 22×22 slab
5.98 cubic yards (296 × 80 lb bags)
for a 22×22 ft slab 4 inches thick: 161.3 cu ft. Bag counts include 10% extra; at 6 inches you need 8.96 yards.
A 22×22 foot slab covers 484 square feet. At the standard 4 inch thickness for a patio, walkway or shed floor, that is 161.3 cubic feet of concrete, or 5.98 cubic yards. At this size ready-mix is cheaper and far less work than bags: about 6.75 yards, roughly $1,114 before delivery fees, against $1,924 for 296 bags of 80 lb mix.
Concrete for a 22×22 slab by thickness
| Thickness | Cubic yards | Cubic feet | 80 lb bags | 60 lb bags | 40 lb bags |
|---|---|---|---|---|---|
| 3 in | 4.48 | 121 | 222 | 296 | 444 |
| 4 in | 5.98 | 161.3 | 296 | 395 | 592 |
| 5 in | 7.47 | 201.7 | 370 | 493 | 740 |
| 6 in | 8.96 | 242 | 444 | 592 | 888 |
| 8 in | 11.95 | 322.7 | 592 | 789 | 1184 |
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: 22 × 22 × 0.333 = 161.33 cu ft.
- Divide by 27 for cubic yards: 161.33 ÷ 27 = 5.975 cu yd.
- Add 10% and divide by the bag yield: 177.47 ÷ 0.6 = 296 bags of 80 lb mix (rounded up).
Under the slab, plan on 4 inches of compacted gravel: about 5.98 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
- 20×22 slab
- 22×24 slab
- 22×25 slab
- 18×22 slab
- 22×26 slab
- 16×22 slab
- 22×28 slab
- 15×22 slab
- 14×22 slab
- 22×30 slab
- 12×22 slab
- 22×32 slab
Questions
- How many bags of concrete do I need for a 22×22 slab?
- At 4 inches thick, a 22×22 slab takes 296 bags of 80 lb concrete mix, 395 bags of 60 lb mix or 592 bags of 40 lb mix, including 10% extra.
- How many yards of concrete for a 22×22 slab?
- 5.98 cubic yards at 4 inches thick, 7.47 at 5 inches and 8.96 at 6 inches, before adding extra for waste.
- How much does a 22×22 concrete slab cost?
- The concrete alone for a 4 inch 22×22 slab costs about $1,924 in 296 bags of 80 lb mix (at about $7 a bag) or about $1,114 for 6.75 yards of ready-mix (at about $165 a yard, before delivery fees). Professionally poured slabs usually run $6 to $12 per square foot, about $2,904 to $5,808 for 484 sq ft.
- How much does a 22×22 slab weigh?
- About 11.7 tons at 4 inches thick (concrete weighs about 145 lb per cubic foot).