Concrete for a 15×22 slab
4.07 cubic yards (202 × 80 lb bags)
for a 15×22 ft slab 4 inches thick: 110 cu ft. Bag counts include 10% extra; at 6 inches you need 6.11 yards.
A 15×22 foot slab covers 330 square feet. At the standard 4 inch thickness for a patio, walkway or shed floor, that is 110 cubic feet of concrete, or 4.07 cubic yards. At this size ready-mix is cheaper and far less work than bags: about 4.5 yards, roughly $743 before delivery fees, against $1,313 for 202 bags of 80 lb mix.
Concrete for a 15×22 slab by thickness
| Thickness | Cubic yards | Cubic feet | 80 lb bags | 60 lb bags | 40 lb bags |
|---|---|---|---|---|---|
| 3 in | 3.06 | 82.5 | 152 | 202 | 303 |
| 4 in | 4.07 | 110 | 202 | 269 | 404 |
| 5 in | 5.09 | 137.5 | 253 | 337 | 505 |
| 6 in | 6.11 | 165 | 303 | 404 | 605 |
| 8 in | 8.15 | 220 | 404 | 538 | 807 |
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 × 15 × 0.333 = 110 cu ft.
- Divide by 27 for cubic yards: 110 ÷ 27 = 4.074 cu yd.
- Add 10% and divide by the bag yield: 121 ÷ 0.6 = 202 bags of 80 lb mix (rounded up).
Under the slab, plan on 4 inches of compacted gravel: about 4.07 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
- 14×22 slab
- 16×22 slab
- 15×20 slab
- 15×24 slab
- 15×25 slab
- 15×18 slab
- 15×26 slab
- 12×22 slab
- 18×22 slab
- 15×16 slab
- 15×28 slab
- 15×15 slab
Questions
- How many bags of concrete do I need for a 15×22 slab?
- At 4 inches thick, a 15×22 slab takes 202 bags of 80 lb concrete mix, 269 bags of 60 lb mix or 404 bags of 40 lb mix, including 10% extra.
- How many yards of concrete for a 15×22 slab?
- 4.07 cubic yards at 4 inches thick, 5.09 at 5 inches and 6.11 at 6 inches, before adding extra for waste.
- How much does a 15×22 concrete slab cost?
- The concrete alone for a 4 inch 15×22 slab costs about $1,313 in 202 bags of 80 lb mix (at about $7 a bag) or about $743 for 4.5 yards of ready-mix (at about $165 a yard, before delivery fees). Professionally poured slabs usually run $6 to $12 per square foot, about $1,980 to $3,960 for 330 sq ft.
- How much does a 15×22 slab weigh?
- About 8 tons at 4 inches thick (concrete weighs about 145 lb per cubic foot).