Concrete by slab thickness (10% waste included)
| Thickness | Ready-mix | 80 lb bags | 60 lb bags |
|---|---|---|---|
| 4 in | 7.82 yd³ | 352 | 470 |
| 5 in | 9.78 yd³ | 440 | 587 |
| 6 in | 11.73 yd³ | 528 | 704 |
Use 4 in for patios and walkways, 5–6 in for driveways and garage floors that carry vehicles.
Frequently asked questions
How many 80 lb bags for a 24x24 slab?
352 bags at 4 in thick, including 10% extra.
How thick should a slab be?
4 inches for patios, sheds and walkways; 5–6 inches for driveways and heavier loads.