Soil for a 4×8 bed at different depths
| Soil depth | Cubic feet | Cubic yards | 1.5 cu ft bags | 2 cu ft bags |
|---|---|---|---|---|
| 6 in | 16 | 0.59 | 11 | 8 |
| 8 in | 21.3 | 0.79 | 15 | 11 |
| 10 in | 26.7 | 0.99 | 18 | 14 |
| 11 in | 29.3 | 1.09 | 20 | 15 |
| 12 in | 32 | 1.19 | 22 | 16 |
| 18 in | 48 | 1.78 | 32 | 24 |
| 24 in | 64 | 2.37 | 43 | 32 |
Building with lumber? A single 2×12 gives about 11 inches of soil depth, two stacked 2×6s also give 11 inches.
Planning this bed
At 4 ft wide you can reach the center from both sides without stepping on the soil — that keeps it loose. The bed has 32 sq ft of growing space. Expect the soil to settle 10–20% in the first season, so keep a few bags of compost to top it up.
The math
Common questions
How many bags of soil for a 4x8 raised bed?
22 bags of 1.5 cu ft for 12 inches deep, or 11 bags for 6 inches.
How many cubic yards for a 4x8 raised bed?
1.19 cubic yards at 12 inches deep.
Want the full method, tips and other sizes? See the raised bed soil calculator guide.