Bags or a truck?
At this size a ready-mix truck is the sensible choice. Mixing 107 bags by hand is a long, heavy day, and the first batches start to set before the last ones are placed.
Concrete slab charts · 12 × 16 ft
How much concrete for a 12×16 slab?
A 12 × 16 ft slab 4 inches thick needs 2.37 cubic yards of concrete (64.0 cubic feet), or about 107 bags of 80 lb premix. Add 5–10% for waste. Other thicknesses are in the table, or adjust the calculator below.
Units
12 × 16 ft slab by thickness
Exact volumes without waste. Bag counts are rounded up.
| Thickness | Cubic yards | Cubic feet | 80 lb bags | 60 lb bags | Metric |
|---|---|---|---|---|---|
| 3 in | 1.78 yd³ | 48.0 ft³ | 80 | 107 | 1.36 m³ |
| 4 in | 2.37 yd³ | 64.0 ft³ | 107 | 143 | 1.81 m³ |
| 5 in | 2.96 yd³ | 80.0 ft³ | 134 | 178 | 2.27 m³ |
| 6 in | 3.56 yd³ | 96.0 ft³ | 160 | 214 | 2.72 m³ |