Raised Bed Soil Calculator — Cubic Feet & Bags
Enter your raised bed size and fill depth to get how much soil you need in cubic feet, cubic yards, and bags.
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How it works
cubic feet = length × width × (depth_in ÷ 12) × beds; bags = ceil(cubic feet ÷ bag size)
Soil to fill one raised bed
| Bed size | Depth | Cubic feet | 1.5 cu ft bags | 2 cu ft bags |
|---|---|---|---|---|
| 4 × 4 ft | 6 in | 8 cu ft | 6 | 4 |
| 4 × 4 ft | 12 in | 16 cu ft | 11 | 8 |
| 4 × 4 ft | 18 in | 24 cu ft | 16 | 12 |
| 4 × 8 ft | 6 in | 16 cu ft | 11 | 8 |
| 4 × 8 ft | 12 in | 32 cu ft | 22 | 16 |
| 4 × 8 ft | 18 in | 48 cu ft | 32 | 24 |
One cubic yard (27 cu ft) fills about a 4×8 bed 10 inches deep and equals about 14 of the 2 cu ft bags. Soil settles, so slightly overfill or top up after the first watering.
Frequently asked questions
How much soil do I need for a 4×8 raised bed?
A 4 ft × 8 ft bed filled 12 inches deep holds 32 cubic feet of soil — about 16 of the 2 cu ft bags, 22 of the 1.5 cu ft bags, or 1.2 cubic yards in bulk. At 6 inches deep it is half that, about 16 cubic feet.
How many bags of soil fill a raised bed?
Divide the bed volume in cubic feet by the bag size. Bagged garden and raised-bed soil comes in 1.5 and 2 cu ft bags, so a 16-cu-ft bed (4×8 at 6 inches) takes about 8 of the 2 cu ft bags or 11 of the 1.5 cu ft bags.
Is bagged or bulk soil cheaper for raised beds?
For one or two small beds, bags are convenient. Above about 1 cubic yard (≈14 of the 2 cu ft bags), bulk delivery is usually cheaper per cubic foot. Many gardeners blend bulk topsoil with bagged compost.