Your Result Explained: Exact Takeoff Breakdown
When re-grading a sunken 20 ft × 30 ft backyard area (600 square feet) after tree stump removal, pool takedown, or drainage correction, an average fill depth of 3 inches (ranging from 1 inch at the edges to 5 inches in the center trough) requires 150.00 net cubic feet of soil—equal to 5.56 cubic yards.
Because uncompacted soil dumped into depressions settles noticeably during the first winter freeze-thaw cycle, adding a 10% compaction factor increases your order to 165.00 cubic feet, or 6.11 cubic yards (6.72 tons at 2,200 lbs/yd³).
Six cubic yards is a single dump-truck load. If your fill depth exceeds 4 inches in the deepest spots, kill or strip the existing grass sod in those deep zones first rather than burying live turf under 4+ inches of dirt (which causes buried grass to rot anaerobically and sink further).
Worked Math: 20 ft × 30 ft Backyard Grading at 3 Inches Average
Computing volume and weight to re-grade a 600 sq ft sunken lawn section with an average 3-inch fill and 10% compaction margin.
- Area = 30 ft × 20 ft = 600 sq ft.
- Average Fill Depth = 3 inches = 0.25 ft.
- Net Volume = 600 sq ft × 0.25 ft = 150.00 cubic feet.
- Net Cubic Yards = 150.00 ÷ 27 = 5.56 cubic yards.
- With 10% Settling Margin = 5.56 × 1.10 = 6.11 cubic yards (165 cu ft).
- Estimated Weight = 6.11 yd³ × 2,200 lbs = 13,442 lbs (6.72 tons).
Bottom Line: Order 6 to 6.5 cubic yards of screened topsoil to grade and compact a 20×30 ft yard at an average 3-inch depth.
How This Scenario Is Calculated
For sloped or dish-shaped depressions, use the average depth across the rectangle—not the maximum depth. If a 20×30 area starts at 0 inches along the perimeter and drops to 6 inches in the middle, the average depth is (0 + 6) ÷ 2 = 3 inches.
At 3 inches deep, every 108 square feet requires 1 net cubic yard of soil (600 ÷ 108 = 5.56 yd³).
Cubic Yards = [Area (sq ft) × (Depth in inches ÷ 12) × (1 + Waste%)] ÷ 27 Tons = (Cubic Yards × Bulk Density in lbs/yd³) ÷ 2,000 Project-Specific Tips & Common Mistakes
Establish a Positive 2% Drainage Slope Away from Foundations
When grading near a house, ensure the soil slopes downward at least 1/4 inch per foot (6 inches over the first 10 feet) away from the foundation wall.
Use a 2×4 Screed Board or Landscape Rake for True Flatness
Drag a straight 8-foot 2×4 board or a 36-inch aluminum grading lute across the loose topsoil to shave high crowns directly into adjacent low pockets.
Mistake Using pure organic compost to fill a 3-inch depression
Recommended Fix: Pure compost oxidizes and shrinks by up to 40% over 2 years as microbes consume organic carbon, causing the low spot to return. Use mineral screened topsoil (at least 80% mineral sand/silt/clay) for permanent elevation changes.
Reference Coverage Table (Screened Loam Topsoil (Dry to Field Moist))
Compare how coverage changes across common depths for Screened Loam Topsoil (Dry to Field Moist) (default planning density 2200 lbs/yd³):
| Depth | 1 Cubic Yard Covers | 1 Ton Covers | Yards / 100 sq ft | Tons / 100 sq ft | Bags (0.75 ft³) / 100 sq ft |
|---|---|---|---|---|---|
| 0.25 in | 1296 sq ft | 1178.2 sq ft | 0.08 yd³ | 0.09 tons | 3 bags |
| 0.5 in | 648 sq ft | 589.1 sq ft | 0.15 yd³ | 0.17 tons | 6 bags |
| 1 in | 324 sq ft | 294.5 sq ft | 0.31 yd³ | 0.34 tons | 12 bags |
| 2 in | 162 sq ft | 147.3 sq ft | 0.62 yd³ | 0.68 tons | 23 bags |
| 4 in | 81 sq ft | 73.6 sq ft | 1.23 yd³ | 1.35 tons | 45 bags |
| 6 in | 54 sq ft | 49.1 sq ft | 1.85 yd³ | 2.04 tons | 67 bags |
Reference Source: USDA NRCS Soil Quality Indicators (Bulk Density) & University of Minnesota Extension.
Frequently Asked Questions
Can existing grass grow through 3 inches of topsoil?
No. Established turfgrass blades can only push through 1/4 to 1/2 inch of topdressing at a time. When adding 3 inches of soil to level a deep dip, plan to overseed or lay fresh sod on top of the leveled area.
Should I use sand or topsoil to level a 20x30 lawn?
For thin topdressing (1/4 to 1/2 inch) on Bermudagrass or closely mowed turf, a 70/30 masonry sand and compost mix works well. For fills deeper than 1 inch on cool-season lawns, use screened loam topsoil matching your native soil texture.
How much topsoil for a 20x30 yard at 1 inch deep?
At 1 inch deep, 600 square feet requires 50 net cubic feet (1.85 cubic yards), or 2.04 cubic yards with 10% settling.
How much does 6 cubic yards of topsoil weigh?
Six cubic yards of dry-to-moist screened topsoil weighs approximately 13,200 lbs (6.6 tons).
Do I need to rent a skid steer for 6 yards of topsoil?
Six yards is manageable by hand with two people and two wheelbarrows in an afternoon, though renting a walk-behind mini skid steer (dingo) turns it into a 45-minute task.