How to calculate how much topsoil you need
Topsoil is sold in bulk by the cubic yard (and sometimes by the ton) and in bags by the cubic foot. Either way, start with the volume of the space you want to fill.
Cubic feet = length (ft) × width (ft) × depth (ft)
Cubic yards = cubic feet ÷ 27
Tons = cubic yards × 1.1 (default density)
Convert the depth from inches to feet by dividing by 12, so 6 inches is 0.5 ft. For round beds use π × radius², and for triangular beds use base × height ÷ 2. Add 5% to 10% for settling: loose soil compacts as it is watered and walked on, so a bed filled exactly to the brim will sink. If you are filling a large raised bed, the cubic yard calculator gives the same volume without the weight and bag details.
Example: a 4 ft × 8 ft raised bed, 12 inches deep
- Volume: 8 × 4 × 1 = 32 cubic feet
- Cubic yards: 32 ÷ 27 = 1.185 cubic yards
- Weight at 1.1 tons per cubic yard: about 1.30 tons
- Bags: 32 one-cubic-foot bags, 16 two-cubic-foot bags, or 43 bags of 0.75 cubic feet
How deep should topsoil be?
Commonly suggested depths are about 4 to 6 inches for establishing a new lawn, 6 to 12 inches for vegetable gardens and raised beds, and a thin layer of a quarter to a half inch when top-dressing an existing lawn. Check any guidance that comes with your seed, sod or plants. The table shows how much soil each depth needs per 1,000 square feet, which is handy for scaling to your own lawn size.
| Depth | Cubic feet | Cubic yards |
|---|---|---|
| 1 in | 83.3 | 3.09 |
| 2 in | 166.7 | 6.17 |
| 3 in | 250 | 9.26 |
| 4 in | 333.3 | 12.35 |
| 6 in | 500 | 18.52 |
| 12 in | 1,000 | 37.04 |
Topsoil weight and density assumptions
The calculator assumes 1.1 US short tons per cubic yard, roughly 2,200 lb. That is a planning figure based on commonly quoted supplier numbers of about 2,000 to 2,700 lb per cubic yard; it is an assumption, not a measurement. Wet soil, soil with a lot of clay and soil screened with sand can all weigh noticeably more, while dry, compost-rich mixes weigh less. Use the density field to enter your supplier’s number if they give one. This matters when you are checking a trailer or truck load limit, so leave yourself a safety margin.
Bags or bulk?
Bags (typically 0.5, 0.75, 1 or 2 cubic feet) are convenient for small beds and containers, but a single cubic yard equals 27 one-cubic-foot bags, which adds up quickly in cost and effort. Once you need more than a cubic yard or two, compare the price of bulk delivery with bags. For a project that also needs mulch or gravel, see the mulch calculator and gravel calculator. If you are laying a new lawn, the sod calculator and grass seed calculator will help with the rest.
Frequently asked questions
How much topsoil do I need for a 1,000 sq ft lawn?
At 4 inches deep you need 333.3 cubic feet, which is 12.35 cubic yards, or about 13.6 tons at 1.1 tons per cubic yard. At 6 inches it is 18.52 cubic yards.
How many tons are in a cubic yard of topsoil?
About 1.1 short tons (roughly 2,200 lb) is a common planning figure, though moisture and composition change it. Ask your supplier and edit the density field if needed.
How many bags of topsoil are in a cubic yard?
A cubic yard is 27 cubic feet: 27 one-cubic-foot bags, 54 half-cubic-foot bags, 36 bags of 0.75 cubic feet, or 13.5 two-cubic-foot bags (round up to 14).
Should I add extra topsoil for settling?
Yes. Adding 5% to 10% is a good habit, because loose soil compacts after watering and rain. Use the extra field in the calculator to add it automatically.
Can I use topsoil in a raised bed?
Many gardeners mix topsoil with compost for raised beds, because topsoil alone can compact. Calculate the total volume with this tool, then split it between topsoil and compost in whatever ratio you prefer.
More free calculators
These calculators give estimates for planning only. Densities, bag sizes and coverage vary by supplier, so confirm quantities before you order.