Use this topsoil calculator to estimate the cubic yards, cubic feet, tons, and whole bags needed for a measured area and finished depth. Enter length and width for a rectangle or use a known square-foot area directly.
How to use the topsoil calculator
Use this for a lawn, raised bed, or planting area when you need an order quantity from surface area and depth. The tons result is an estimate because moisture and compaction change delivered soil weight.
For a rectangle, multiply length by width. For an irregular area, divide it into simple sections and enter their combined square footage.
Enter the average depth of the topsoil layer, not the excavation depth before grading.
Cubic yards are geometric volume. Weight changes with soil composition and moisture, so supplier density is better for ordering by weight.
Example: 20 × 15 ft at 4 in deep
- A 20 × 15 ft area is 300 sq ft.
- At 4 in deep, it needs 100 cu ft, or 3.70 cu yd of topsoil.
- Using the transparent 2,400 /yd³ planning midpoint, that is about 4.44 short tons, or 134 bags at 0.75 cu ft each.
How cubic yards are calculated
The calculator multiplies area by depth after converting the depth to feet. It then divides cubic feet by 27 to get cubic yards. An optional allowance is applied only after the exact geometric volume is known.
Why bags and tons can disagree
Bag count uses the volume printed on one bag and always rounds up to a whole bag. Tons use an estimated bulk density. Those are separate conversions, so bag weight should not be substituted for bag volume.