Concrete for a 22×28 slab
7.6 cubic yards (377 × 80 lb bags)
for a 22×28 ft slab 4 inches thick: 205.3 cu ft. Bag counts include 10% extra; at 6 inches you need 11.41 yards.
A 22×28 foot slab covers 616 square feet. At the standard 4 inch thickness for a patio, walkway or shed floor, that is 205.3 cubic feet of concrete, or 7.6 cubic yards. At this size ready-mix is cheaper and far less work than bags: about 8.5 yards, roughly $1,403 before delivery fees, against $2,451 for 377 bags of 80 lb mix.
Concrete for a 22×28 slab by thickness
| Thickness | Cubic yards | Cubic feet | 80 lb bags | 60 lb bags | 40 lb bags |
|---|---|---|---|---|---|
| 3 in | 5.7 | 154 | 283 | 377 | 565 |
| 4 in | 7.6 | 205.3 | 377 | 502 | 753 |
| 5 in | 9.51 | 256.7 | 471 | 628 | 942 |
| 6 in | 11.41 | 308 | 565 | 753 | 1130 |
| 8 in | 15.21 | 410.7 | 753 | 1004 | 1506 |
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: 28 × 22 × 0.333 = 205.33 cu ft.
- Divide by 27 for cubic yards: 205.33 ÷ 27 = 7.605 cu yd.
- Add 10% and divide by the bag yield: 225.87 ÷ 0.6 = 377 bags of 80 lb mix (rounded up).
Under the slab, plan on 4 inches of compacted gravel: about 7.6 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
- 22×26 slab
- 22×30 slab
- 20×28 slab
- 24×28 slab
- 22×25 slab
- 25×28 slab
- 22×24 slab
- 22×32 slab
- 18×28 slab
- 26×28 slab
- 22×22 slab
- 16×28 slab
Questions
- How many bags of concrete do I need for a 22×28 slab?
- At 4 inches thick, a 22×28 slab takes 377 bags of 80 lb concrete mix, 502 bags of 60 lb mix or 753 bags of 40 lb mix, including 10% extra.
- How many yards of concrete for a 22×28 slab?
- 7.6 cubic yards at 4 inches thick, 9.51 at 5 inches and 11.41 at 6 inches, before adding extra for waste.
- How much does a 22×28 concrete slab cost?
- The concrete alone for a 4 inch 22×28 slab costs about $2,451 in 377 bags of 80 lb mix (at about $7 a bag) or about $1,403 for 8.5 yards of ready-mix (at about $165 a yard, before delivery fees). Professionally poured slabs usually run $6 to $12 per square foot, about $3,696 to $7,392 for 616 sq ft.
- How much does a 22×28 slab weigh?
- About 14.9 tons at 4 inches thick (concrete weighs about 145 lb per cubic foot).