Raised bed soil calculator
Enter your bed's inside dimensions to estimate how much soil mix to buy. Results are estimates; soil blends settle by different amounts.
Example estimate (4 × 8 ft bed, 12 in deep)
- Cubic feet
- 32.0
- Cubic yards
- 1.19
- Liters
- 906
- Bags needed
- 22 × 1.5 cu ft
How the calculator works
Rectangular beds: length × width × (depth ÷ 12) = cubic feet. Round beds: 3.1416 × (diameter ÷ 2)² × (depth ÷ 12). The total is multiplied by the number of beds and by any settling allowance you choose. Cubic yards = cubic feet ÷ 27; liters = cubic feet × 28.317. Bag counts are rounded up to whole bags.
Tips for accurate results
- Measure the inside of the frame, not the outside.
- Use the depth you plan to fill, usually an inch or two below the rim.
- Lumber is smaller than its name: two stacked 2×6 boards are about 11 inches tall.
- Check bag labels; some list quarts or liters rather than cubic feet.
This tool estimates volume only. For what the soil should contain, read understanding soil mixes for raised beds and how to calculate soil for a raised bed.