How to Calculate Soil Volume in Cubic Yards & Feet
Whether you are leveling a bumpy lawn, backfilling a retaining wall, or planting landscape flower beds, calculating bulk soil volume is essential. Bulk soil suppliers sell topsoil, garden soil, and compost by the cubic yard. Ordering soil without calculating exact volume leads to either extra delivery fees or huge unwanted piles of soil left on your driveway.
Converting garden square footage into cubic yards requires three simple mathematical steps.
Open Soil Calculator
The Soil Volume Formula (Cubic Yards)
Volume calculation multiplies surface area by depth, then divides by 27 (the number of cubic feet in one cubic yard):
Practical Soil Calculation Example
Suppose you are building a large flower garden measuring 20 feet long by 15 feet wide and need to topdress it with 4 inches of fresh topsoil blend:
- Calculate Surface Area: 20 ft x 15 ft = 300 square feet.
- Convert Depth to Feet: 4 inches / 12 = 0.333 feet.
- Calculate Cubic Feet Volume: 300 sq ft x 0.333 ft = 100 cubic feet.
- Convert to Cubic Yards: 100 / 27 = 3.70 Cubic Yards.
Quick Soil Coverage Reference Chart (1 Cubic Yard)
One cubic yard of topsoil equals 27 cubic feet. The table below shows how many square feet one cubic yard covers at various depth settings:
| Soil Depth | Depth in Feet | Coverage per Cubic Yard | Typical Use Case |
|---|---|---|---|
| 1 Inch (2.5 cm) | 0.083 ft | 324 sq ft | Lawn overseeding & light topdressing |
| 2 Inches (5.0 cm) | 0.167 ft | 162 sq ft | Grading low spots in existing turf |
| 3 Inches (7.5 cm) | 0.250 ft | 108 sq ft | New flower bed installation |
| 6 Inches (15.0 cm) | 0.500 ft | 54 sq ft | Shallow raised beds & vegetable garden plots |
| 12 Inches (30.0 cm) | 1.000 ft | 27 sq ft | Deep raised beds & planter boxes |
To calculate exact volume and retail bag counts for your project dimensions, use our free Soil Calculator.
