How Much Topsoil Do I Need? (By Depth & Area)
Part of Landscaping & Aggregate
Quick answer
Topsoil needed (yd³) = area (ft²) × depth (ft) ÷ 27. For a new lawn use 4–6 inches of soil; for garden and raised beds use 8–12 inches. Example: a 1,000 ft² lawn at 4 inches deep needs about 12.3 cubic yards (≈ 13.5 tons).
Topsoil is sold by the cubic yard in bulk (or by the bag for small jobs), so the goal is turning your area and target depth into cubic yards. The depth depends entirely on what you're doing — top-dressing a lawn needs little; filling a bed needs a lot.
Recommended soil depth by job
| Job | Depth | Per 100 ft² |
|---|---|---|
| Top-dressing an existing lawn | 0.25–0.5 in | ~0.08–0.15 yd³ |
| New lawn / sod prep | 4–6 in | ~1.2–1.9 yd³ |
| Garden / flower beds | 8–12 in | ~2.5–3.7 yd³ |
| Raised beds | 10–12 in | ~3.1–3.7 yd³ |
The formula
- Cubic yards = length ft × width ft × (depth in ÷ 12) ÷ 27.
- One cubic yard covers about 100 ft² at 3 inches deep, or 300 ft² at 1 inch.
- Bags: a 40 lb bag holds ~0.75 ft³, so it takes ~36 bags to equal one cubic yard.
Enter your area and depth in the topsoil calculator to get cubic yards and tons, since bulk soil is often trucked and priced by weight.
FAQs
How many cubic yards of topsoil do I need for a raised bed?
Multiply the bed's length × width × depth (in feet) and divide by 27. A 4 ft × 8 ft bed filled 10 inches deep needs about 0.99 cubic yards — just under one yard.
How much does a cubic yard of topsoil cover?
About 100 square feet at 3 inches deep, 150 ft² at 2 inches, or 300 ft² at 1 inch. Deeper applications cover less area per yard.