Estimate the soil volume for a rectangular raised bed. Use the inside measurements and the depth you actually need to fill.
How much soil do you need?
Calculate by hand
Cubic feet = length in feet × width in feet × fill depth in inches ÷ 12. Divide cubic feet by 27 for cubic yards. To estimate bags, divide by the cubic feet stated on each bag and round up to a whole bag.
Common raised bed sizes
These examples assume an empty rectangular bed filled 12 inches deep.
| Inside dimensions | Cubic feet | 2 cu. ft. bags |
|---|---|---|
| 2 × 4 feet | 8 | 4 |
| 4 × 4 feet | 16 | 8 |
| 4 × 8 feet | 32 | 16 |
| 4 × 12 feet | 48 | 24 |
Before ordering soil
For a partially filled bed, enter only the depth you need to add. Measure inside the bed walls, and calculate separate sections individually if the bed is not rectangular. Ask your supplier about settling and delivery increments. This estimate measures volume; it does not select a soil blend or prescribe a planting depth for every crop.
Plan your planting
Once you know your bed size, choose seeds that suit its sunlight, spacing and your growing season. Explore Gardeners Basics seeds and garden kits, then follow each seed packet's planting instructions.
