Bags or a truck?
At this size a ready-mix truck is the sensible choice. Mixing 320 bags by hand is a long, heavy day, and the first batches start to set before the last ones are placed.
Concrete slab charts · 24 × 24 ft
How much concrete for a 24×24 slab?
A 24 × 24 ft slab 4 inches thick needs 7.11 cubic yards of concrete (192.0 cubic feet), or about 320 bags of 80 lb premix. Add 5–10% for waste. Other thicknesses are in the table, or adjust the calculator below.
Units
24 × 24 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 | 5.33 yd³ | 144.0 ft³ | 240 | 320 | 4.08 m³ |
| 4 in | 7.11 yd³ | 192.0 ft³ | 320 | 427 | 5.44 m³ |
| 5 in | 8.89 yd³ | 240.0 ft³ | 400 | 534 | 6.80 m³ |
| 6 in | 10.67 yd³ | 288.0 ft³ | 480 | 640 | 8.16 m³ |