How Much Topsoil Do You Need? The Quick Calculation
One cubic yard covers 54 square feet at 6 inches deep. Here is how to calculate exact quantities for any project.
The formula: Length (feet) × Width (feet) × Depth (inches) / 12 = cubic feet. Divide by 27 for cubic yards. A 10×4 foot raised bed at 12 inches deep: 10 × 4 × 12 / 12 = 40 cubic feet = 1.5 cubic yards. At $35-55 per cubic yard delivered, that is $52-82 in bulk — versus $200+ if you buy forty 1-cubic-foot bags at $5 each.
Bulk vs Bags
For anything over 2 cubic yards (about 54 cubic feet), always buy bulk. Bulk soil costs $25-55 per cubic yard. Bagged soil costs $135-216 per cubic yard equivalent. That is 3-4 times more expensive for the same dirt. Most landscape supply companies deliver for $50-100 within a 15-mile radius and dump it in your driveway.