How Much Topsoil Do I Need? Lawn and Garden Table
How deep to spread topsoil for lawns and beds, a cubic yard table for common areas, and why to order extra for settling.
Topsoil is bought by the cubic yard or by the bag, and it always settles once it’s spread and watered. Work out the volume from the area and the depth, then add a little extra.
How deep should topsoil be?
- New lawn from seed or sod: 4–6”. The City of Charlottesville’s Healthy Lawns guide puts it simply: “The key is 4-6” of quality topsoil.”
- Topdressing an existing lawn: a thin layer, about ¼–½”, raked into the grass.
- Filling low spots: fill in thin layers of an inch or two, letting the grass grow through between layers.
- New garden beds: 6–12”, mixed with compost. For raised beds, see Raised Bed Soil.
Mix the new topsoil into the top few inches of the existing ground rather than laying it on hard subsoil. A sharp line between two different soils can stop water and roots moving down.
The formula
- Area in square feet = length × width.
- Cubic feet = area × depth in inches ÷ 12.
- Add 15% for settling.
- Cubic yards = cubic feet ÷ 27.
Example: a 500 sq ft lawn at 4” is 167 cubic feet. With 15% extra, that’s 191.7 cubic feet, or 7.1 cubic yards.
Topsoil table
Cubic yards including 15% for settling.
| Area | 2” deep | 4” deep | 6” deep |
|---|---|---|---|
| 100 sq ft | 0.71 yd | 1.42 yd | 2.13 yd |
| 250 sq ft | 1.77 yd | 3.55 yd | 5.32 yd |
| 500 sq ft | 3.55 yd | 7.1 yd | 10.65 yd |
| 1000 sq ft | 7.1 yd | 14.2 yd | 21.3 yd |
| 2000 sq ft | 14.2 yd | 28.4 yd | 42.59 yd |
| 5000 sq ft | 35.49 yd | 70.99 yd | 106.48 yd |
Bags or bulk?
A typical bag of topsoil holds 0.75 cubic feet, so it takes 36 bags to make one cubic yard. Bags make sense for patching and small beds. For a new lawn, bulk delivery is far cheaper per yard. A cubic yard of topsoil weighs over a ton (more when wet), so have it dumped as close to the work as possible.
Buying good topsoil
- Ask what’s in it. “Screened topsoil” has had stones and roots removed. Blended products may include compost or sand.
- Look at it, or ask for a sample. It should be dark, crumbly and smell earthy, with no trash, large stones or chunks of clay.
- Ask about weeds. Soil from a reputable yard is less likely to bring weed seeds or invasive roots.
- Test your soil if you’re unsure what it needs. Many university extension offices offer low-cost soil tests.
Work out topsoil, mulch and raised bed soil in the Raised Bed, Soil & Mulch Planner. For mulch depths and coverage, see How Much Mulch Do You Need?