14×14 slab: concrete by thickness
| Thickness | Cu ft | Cu yd | 80 lb bags | 60 lb bags |
|---|---|---|---|---|
| 3.5″ | 57.17 | 2.12 | 96 | 128 |
| 4″ | 65.33 | 2.42 | 109 | 146 |
| 5″ | 81.67 | 3.02 | 137 | 182 |
| 6″ | 98.00 | 3.63 | 164 | 218 |
No waste included in the table.
Worked example
14 ft × 14 ft = 196 sq ft. At 4 inches: 196 × 4 ÷ 12 = 65.33 cu ft, or 2.42 cubic yards. With 10% extra that is 2.66 yd³, or 120 bags of 80 lb mix.
At over 1 cubic yard, compare the cost and labor of bags against a ready-mix delivery.
Assumes standard concrete mix bag yields: 80 lb ≈ 0.60 cu ft, 60 lb ≈ 0.45 cu ft. Check the yield on your bag. 1 cubic yard = 27 cubic feet.
Frequently asked questions
How many bags of concrete for a 14×14 slab?
109 × 80 lb or 146 × 60 lb bags at 4 inches thick, before waste.
How many yards of concrete for a 14×14 slab?
2.42 cubic yards at 4 inches; 3.63 at 6 inches.