Concrete for a 8×22 slab
2.17 cubic yards (108 × 80 lb bags)
for a 8×22 ft slab 4 inches thick: 58.7 cu ft. Bag counts include 10% extra; at 6 inches you need 3.26 yards.
A 8×22 foot slab covers 176 square feet. At the standard 4 inch thickness for a patio, walkway or shed floor, that is 58.7 cubic feet of concrete, or 2.17 cubic yards. At this size you can mix 108 bags of 80 lb (about $702 and a long day of mixing) or order 2.5 yards of ready-mix (about $413, plus the short-load fee most suppliers charge under 3 to 4 yards).
Concrete for a 8×22 slab by thickness
| Thickness | Cubic yards | Cubic feet | 80 lb bags | 60 lb bags | 40 lb bags |
|---|---|---|---|---|---|
| 3 in | 1.63 | 44 | 81 | 108 | 162 |
| 4 in | 2.17 | 58.7 | 108 | 144 | 216 |
| 5 in | 2.72 | 73.3 | 135 | 180 | 269 |
| 6 in | 3.26 | 88 | 162 | 216 | 323 |
| 8 in | 4.35 | 117.3 | 216 | 287 | 431 |
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 × 8 × 0.333 = 58.67 cu ft.
- Divide by 27 for cubic yards: 58.67 ÷ 27 = 2.173 cu yd.
- Add 10% and divide by the bag yield: 64.53 ÷ 0.6 = 108 bags of 80 lb mix (rounded up).
Under the slab, plan on 4 inches of compacted gravel: about 2.17 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
- 8×20 slab
- 8×24 slab
- 8×25 slab
- 8×18 slab
- 8×26 slab
- 6×22 slab
- 10×22 slab
- 8×16 slab
- 8×28 slab
- 8×15 slab
- 8×14 slab
- 8×30 slab
Questions
- How many bags of concrete do I need for a 8×22 slab?
- At 4 inches thick, a 8×22 slab takes 108 bags of 80 lb concrete mix, 144 bags of 60 lb mix or 216 bags of 40 lb mix, including 10% extra.
- How many yards of concrete for a 8×22 slab?
- 2.17 cubic yards at 4 inches thick, 2.72 at 5 inches and 3.26 at 6 inches, before adding extra for waste.
- How much does a 8×22 concrete slab cost?
- The concrete alone for a 4 inch 8×22 slab costs about $702 in 108 bags of 80 lb mix (at about $7 a bag) or about $413 for 2.5 yards of ready-mix (at about $165 a yard, before delivery fees). Professionally poured slabs usually run $6 to $12 per square foot, about $1,056 to $2,112 for 176 sq ft.
- How much does a 8×22 slab weigh?
- About 4.3 tons at 4 inches thick (concrete weighs about 145 lb per cubic foot).