How to Use This Calculator
Enter your area in feet and the depth of topsoil you need in inches. For a new garden bed starting from bare ground, 6 inches is the standard. To topdress an existing lawn, 1 to 2 inches is typical. For raised beds, measure the interior dimensions and the depth you want to fill. The result shows cubic yards for bulk ordering, the equivalent number of 0.75 cu ft bags, and a cost range based on current bulk and retail pricing. A 10% settling allowance is already included. For L-shaped beds or multiple separate areas, calculate each section individually and add the cubic yard totals. If you need topsoil for a raised bed specifically, see our Raised Bed Topsoil Calculator for bed-specific guidance.
How to Calculate Topsoil Quantity
Topsoil quantity: Cubic Yards = (Length × Width × Depth in feet) ÷ 27. Depth in feet = depth in inches ÷ 12.
Quick reference: how much topsoil covers 100 square feet at different depths:
| Depth | Cubic feet per 100 sq ft | Cubic yards per 100 sq ft |
|---|---|---|
| 1 inch (topdressing) | 8.3 cu ft | 0.31 yd³ |
| 2 inches | 16.7 cu ft | 0.62 yd³ |
| 4 inches | 33.3 cu ft | 1.23 yd³ |
| 6 inches | 50 cu ft | 1.85 yd³ |
| 12 inches | 100 cu ft | 3.70 yd³ |
Worked example: a 500 sq ft area for a new lawn at 4 inches. Cubic feet = 500 × (4 ÷ 12) = 166.7. Cubic yards = 166.7 ÷ 27 = 6.17. With 10% settling: 6.17 × 1.1 = 6.79 cubic yards. Order 7 cubic yards.
Getting the Right Amount of Topsoil
Order about 10 to 15% more than you calculate. Topsoil settles after the first watering cycles. A bed filled level at delivery will typically drop 1 to 2 inches after rain and watering, especially if the soil is loose and airy. The settling allowance in the calculator accounts for this, but for areas where final grade matters (slopes, drainage swales), add another 5% on top.
Test your existing soil before ordering. If your existing soil has good structure and adequate organic matter, you may only need 2 to 3 inches of topsoil to amend the surface rather than 6 inches of full replacement. A simple test: dig a 12-inch hole and fill it with water. If it drains within an hour, your subsoil has decent drainage and you may need less new material than you think.
For lawns, mix new topsoil into the existing surface rather than simply laying it on top. Rototill the old and new soil together to a depth of 6 to 8 inches. This prevents a hard layer from forming at the boundary between old and new soil, which can block water movement and trap roots.
What to Buy
For small projects under 1 cubic yard, 0.75 cu ft bags from a hardware or garden store work well. Most big-box stores stock topsoil and garden soil blends year-round. Note that "garden soil" is different from "topsoil": garden soil contains added compost and amendments and costs more, but is better suited for container gardens and raised beds.
For larger projects, call at least two local landscape suppliers and ask for "screened topsoil" or "screened loam." Unscreened topsoil can contain rocks and debris. Prices range from $25 to $55 per cubic yard delivered, depending on location and material quality. Spring delivery tends to be more expensive due to high demand. Order in late summer or fall for the best pricing.