How much gravel for 400 square feet?
At 3 inches deep, 400 square feet needs 3.70 cubic yards of gravel, or about 200 bags (0.5 cu ft (50 lb) each).
Crushed stone weighs about 1.4 tons per cubic yard; it varies by stone type.
| Depth | Cubic yards | 0.5 cu ft (50 lb) bags | Tons |
|---|---|---|---|
| 2 in | 2.47 | 134 | 3.46 |
| 3 in | 3.70 | 200 | 5.19 |
| 4 in | 4.94 | 267 | 6.91 |
1 cubic yard = 27 cubic feet. Bulk delivery is usually cheaper than bags above about 1 to 2 cubic yards.