How Much Topsoil Do I Need?
The amount of topsoil you need depends on your area and intended depth. Lawn top-dressing needs just 1–2 inches; raised beds from scratch need 8–12 inches.
🧮Topsoil Calculator — cubic yards and 40 lb bags
Enter your exact dimensions for a personalized estimate →
The quick formula
Volume (cu yd) = Length (ft) × Width (ft) × Depth (in) ÷ 324
40 lb bags = Volume (cu ft) ÷ 0.75, rounded up
Depth guide by project type
| Project | Recommended depth |
|---|---|
| Lawn top-dressing | 1–2 inches |
| Overseeding prep | 2–3 inches |
| New lawn / sod base | 4–6 inches |
| Garden beds (existing) | 3–4 inches |
| New garden beds | 6–8 inches |
| Raised beds (from scratch) | 8–12 inches |
Coverage table — cubic yards needed per 100 sq ft
| Depth | Cu yd needed | 40 lb bags |
|---|---|---|
| 1” | 0.31 | 11 |
| 2” | 0.62 | 22 |
| 4” | 1.23 | 45 |
| 6” | 1.85 | 67 |
| 8” | 2.47 | 89 |
| 12” | 3.70 | 133 |
Quick examples
| Project | Size | Depth | Cu Yd | 40 lb bags |
|---|---|---|---|---|
| Lawn patch | 10 × 20 ft | 2” | 1.23 | 45 |
| Garden bed | 4 × 8 ft | 6” | 0.59 | 22 |
| Raised bed | 4 × 8 ft | 12” | 1.19 | 43 |
How to measure
- Measure length and width of your bed or lawn area in feet.
- Decide on depth using the table above for your project type.
- Subtract obstacles — tree trunks, existing large plants, pathways.
- Add 5% overage to account for settling and uneven ground.
For irregular shapes or multiple beds, use the Topsoil Calculator with the Irregular shape option.
Frequently Asked Questions
How many cubic yards of topsoil do I need for a 10×10 garden bed at 6 inches deep?
A 10×10 ft bed (100 sq ft) at 6 inches deep needs 1.85 cubic yards. That is about 67 bags of 40 lb topsoil, or roughly 2 tons of bulk topsoil.
How many 40-lb bags of topsoil equal a cubic yard?
It takes 36 bags of 40 lb topsoil to fill one cubic yard, since each bag yields about 0.75 cubic feet and there are 27 cubic feet in a cubic yard (27 ÷ 0.75 = 36).
How much does a yard of topsoil weigh?
Topsoil typically weighs around 2,200 lbs (1.1 tons) per cubic yard. Weight varies with moisture content — wet topsoil can weigh significantly more.
How deep should I add topsoil for a lawn?
For lawn top-dressing, 1–2 inches is enough. For new sod or seeding, 4–6 inches of good topsoil promotes strong root development. For raised beds, 8–12 inches.
When should I order bulk topsoil vs. bags?
Order bulk delivery for projects over 1.5–2 cubic yards — it is much cheaper per yard. Use bags for small patches, tight-access areas, or when you only need a fraction of a yard.