Cedar Raised Bed Soil Calculator: How Much You Need
By Greenes Fence Company: Cedar Raised Garden Beds ... | Published: 2026-10-17
Category: How-to Guides
Learn how to calculate the exact cubic feet of soil for your cedar raised garden bed. Avoid overbuying or underfilling with this simple guide.
Quick answer
Multiply the bed's length (ft) by width (ft) by depth (ft) to get cubic feet. For a 4 ft x 8 ft x 10.5 in bed, that's 4 × 8 × 0.875 = 28 cubic feet. Always round up by 10% to account for settling.
Why Accurate Soil Volume Matters
Ordering too little soil leaves your bed half-empty and delays planting. Ordering too much wastes money and creates a disposal problem. Using the right volume also ensures your plants have enough root space and that the bed drains properly.
How to calculate your soil volume
- Measure the interior length and width: Use a tape measure inside the bed, not the outer edges. For a standard 4x8 bed, the interior is usually very close to 4 ft by 8 ft, but always check your specific model. Common mistake: measuring the outer dimensions, which overestimates volume.
- Convert depth to feet: Divide the depth in inches by 12. A 10.5-inch-deep bed becomes 10.5 ÷ 12 = 0.875 ft. For a 12-inch bed, it's exactly 1 ft. Checkpoint: use decimal feet, not inches, in the final calculation.
- Multiply length × width × depth: Multiply the three numbers: length (ft) × width (ft) × depth (ft) = cubic feet. For a 4x8 bed at 10.5 inches: 4 × 8 × 0.875 = 28 cubic feet. Add 10% for settling: 28 × 1.1 = 30.8 cubic feet. Order 31 cubic feet.
Product facts
- Premium Cedar Raised Garden Bed with CritterGuard® Cedar Fence System 4 ft x 8 ft x 10.5 in (3/4 in Thick) RC6T21BCG: The Premium Cedar Raised Garden Bed with CritterGuard® Cedar Fence System measures 4 ft x 8 ft x 10.5 in (3/4 in thick boards). Knowing the exact interior dimensions lets you calculate soil volume precisely. For this 10.5-inch-deep bed, use 0.875 ft for depth in the formula.
