How much topsoil for 400 square feet?
At 4 inches deep, 400 square feet needs 4.94 cubic yards of topsoil, or about 178 bags (0.75 cu ft (40 lb) each).
Topsoil weighs about 1.1 tons per cubic yard, more when wet.
| Depth | Cubic yards | 0.75 cu ft (40 lb) bags | 1 cu ft bags | Tons |
|---|---|---|---|---|
| 2 in | 2.47 | 89 | 67 | 2.72 |
| 4 in | 4.94 | 178 | 134 | 5.43 |
| 6 in | 7.41 | 267 | 200 | 8.15 |
1 cubic yard = 27 cubic feet. Bulk delivery is usually cheaper than bags above about 1 to 2 cubic yards.