CALCULATION METHOD
How much topsoil do I need?
Measure the surface area, multiply by the planned depth, and convert the resulting volume to cubic yards. The calculator then adds your order allowance and converts that order volume to an estimated weight and bag count.
Cubic feet = area in sq ft × depth in inches ÷ 12
Cubic yards = cubic feet ÷ 27
Order volume = net volume × (1 + allowance ÷ 100)
Bags = order cubic feet ÷ bag volume, rounded up
20 × 10 ft topsoil example
A 20 ft × 10 ft area covered 3 inches deep needs 50 cubic feet, or 1.85 cubic yards, before allowance. Adding 10% produces an order estimate of 2.04 cubic yards. At the editable default density of 81.2 lb/ft³, that is about 2.23 short tons, or 74 bags when each bag contains 0.75 ft³.
Topsoil coverage per cubic yard
One cubic yard contains 27 cubic feet. The table shows theoretical level coverage before any allowance for settling or grade variation.
| Depth | Coverage from 1 cubic yard |
|---|---|
| 1 inch | 324 sq ft |
| 2 inches | 162 sq ft |
| 3 inches | 108 sq ft |
| 4 inches | 81 sq ft |
| 6 inches | 54 sq ft |
Why topsoil tons vary
Weight is less predictable than volume. USDA NRCS explains that bulk density depends on texture, organic matter, pore space, and compaction; typical soil bulk densities span roughly 1.0–1.7 g/cm³. The calculator starts at 1.30 g/cm³ (about 81.2 lb/ft³), but delivered topsoil may differ, especially when wet. Use the supplier’s loose-volume density whenever available.
Bulk topsoil or bags?
Bulk suppliers commonly sell by cubic yard, while bagged products state a volume in cubic feet. Because bag weight does not uniquely determine volume, enter the package volume from the label. Compare the calculated bulk volume and bag count with delivery minimums and access constraints.
Topsoil depth is project-specific
The preset buttons are measurement shortcuts, not universal recommendations. Existing soil condition, final grade, turf or plant requirements, and expected settlement all matter. Use the depth in your landscape plan or confirm it with the installer, supplier, or local extension service.
USDA NRCS bulk-density guide for soil density variability and typical range; University of Illinois Extension for the length × width × depth ÷ 27 cubic-yard method. Accessed September 11, 2026.