How much topsoil per square foot?
| Depth | 1 cubic yard covers | Cubic yards per 1,000 sq ft | 1 cu ft bags per 100 sq ft |
|---|---|---|---|
| 1 inch | 324 sq ft | 3.09 | 9 |
| 2 inches | 162 sq ft | 6.17 | 17 |
| 3 inches | 108 sq ft | 9.26 | 25 |
| 4 inches | 81 sq ft | 12.35 | 34 |
| 6 inches | 54 sq ft | 18.52 | 50 |
| 8 inches | 41 sq ft | 24.69 | 67 |
| 12 inches | 27 sq ft | 37.04 | 100 |
These figures are exact volume, with no allowance for settling. A layer 6 inches deep over 1,000 square feet takes about 18.5 cubic yards, which is why topsoil for a new lawn is almost always bought in bulk.
How deep should topsoil be?
- New lawn: 4 to 6 inches. Penn State Extension recommends a minimum of 4 to 6 inches (firmed or settled depth) of good-quality topsoil for good turf, and suggests working about 2 inches of it into the top 2 to 3 inches of the subsoil underneath so the layers blend. If you're adding several inches, lower the subgrade first so the finished lawn meets paths and doorways at the right height.
- Raised vegetable beds: 8 to 12 inches when the ground below is poor. Colorado State University Extension says that where the soil below isn't suitable for crop growth, 8 to 12 inches of soil is considered minimal. If roots can grow down into decent soil under the bed, a lower bed works too.
- Let it settle before you seed. Penn State notes that rain or irrigation can settle new soil instead of rolling it; spread a little extra, water it, and rake it level before seeding or sodding.
How much soil for a raised bed?
| Bed | Cubic feet | Cubic yards | 1.5 cu ft bags | 2 cu ft bags |
|---|---|---|---|---|
| 3 × 6 ft, 10 in deep | 15.0 | 0.56 | 10 | 8 |
| 4 × 4 ft, 10 in deep | 13.3 | 0.49 | 9 | 7 |
| 4 × 8 ft, 6 in deep | 16.0 | 0.59 | 11 | 8 |
| 4 × 8 ft, 10 in deep | 26.7 | 0.99 | 18 | 14 |
| 4 × 8 ft, 12 in deep | 32.0 | 1.19 | 22 | 16 |
| 4 × 12 ft, 12 in deep | 48.0 | 1.78 | 32 | 24 |
Fill to the depth of soil you want, not the height of the boards; most people leave an inch or two of the frame showing. For several beds, compare prices: one cubic yard of bulk mix is 27 cubic feet, the same as about 14 bags of 2 cu ft or 18 bags of 1.5 cu ft, so check your supplier's delivered price per yard against the bag price before you buy.
How the calculator works
Volume is area × depth, with the depth converted from inches to feet. A 20 × 10 ft area is 200 square feet; at 4 inches that's 200 × 4 ÷ 12 = 66.7 cubic feet. Adding 10% for settling gives 73.3 cubic feet. Divide by 27 for cubic yards (2.72) or by the bag size for bags (74 bags of 1 cubic foot). Bags are rounded up. For a circle, the area is π × radius².
FAQ
How many bags of topsoil are in a yard?
A cubic yard is 27 cubic feet: 36 bags of 0.75 cubic feet, 27 bags of 1 cubic foot, 18 bags of 1.5 cubic feet, or 13.5 bags of 2 cubic feet.
How much topsoil do I need for 1,000 square feet?
At 4 inches, 12.35 cubic yards; at 6 inches, 18.52 cubic yards. Add your settling allowance on top (10% makes those about 13.6 and 20.4 yards).
How much soil for a 4 × 8 raised bed?
At 10 inches deep, 26.7 cubic feet, or just under 1 cubic yard: 18 bags of 1.5 cubic feet or 14 bags of 2 cubic feet. At 12 inches it's 32 cubic feet.
Topsoil, garden soil, or raised-bed mix?
The volume math is the same for all of them. Topsoil is for filling and grading lawns and beds; bagged garden soil and raised-bed mixes usually have compost or other organic matter mixed in. Check the bag for what's in it.
How much does a yard of topsoil weigh?
It depends heavily on how wet the soil is and what's in it, so ask your supplier before you plan to haul it in a pickup. This calculator works in volume, which is how topsoil is sold. For stone sold by the ton, use the gravel calculator.
Sources: Penn State Extension, Lawn Establishment (topsoil depth, blending, settling); Colorado State University Extension, Block Style Layout in Raised Bed Vegetable Gardens (CMG GardenNotes #713, raised bed soil depth).