How much topsoil do I need?
Work out the area you want to cover, choose the depth, and the calculator returns the volume in cubic yards. Topsoil is sold by the cubic yard for bulk deliveries and by the cubic foot in bags. If you are filling raised beds, use the full depth of the bed.
Recommended topsoil depth
| Project | Typical depth |
|---|---|
| Topdressing an existing lawn | 0.25 to 0.5 inch |
| Levelling low spots in a lawn | 1 to 2 inches at a time |
| New lawn from seed or turf | 4 to 6 inches |
| Flower and vegetable beds | 6 to 12 inches |
| Raised beds | Full depth of the bed, often 8 to 12 inches |
Quick formula: cubic yards = length (ft) × width (ft) × depth (in) ÷ 324. For example, a 10 ft × 10 ft area at 3 inches deep is 10 × 10 × 3 ÷ 324 = 0.93 cubic yards. The calculator above does this for you and adds the waste allowance.
Worked examples
New lawn. A plot 30 ft by 40 ft at 4 inches deep is 400 cubic feet, which is 14.8 cubic yards. With 5% waste that is about 15.6 cubic yards.
Raised bed. A bed 4 ft by 8 ft filled 12 inches deep holds 32 cubic feet, or 1.19 cubic yards. Many raised beds use a mix of topsoil and compost, so check the proportions you want.
Thin topdressing. A lawn of 1,000 square feet with half an inch of topsoil needs about 41.7 cubic feet, or 1.5 cubic yards.
How far does a cubic yard of topsoil go?
| Depth | Area covered by 1 cubic yard | Cubic yards for 100 sq ft |
|---|---|---|
| 1 inch | 324 sq ft | 0.31 |
| 2 inches | 162 sq ft | 0.62 |
| 3 inches | 108 sq ft | 0.93 |
| 4 inches | 81 sq ft | 1.23 |
| 6 inches | 54 sq ft | 1.85 |
| 12 inches | 27 sq ft | 3.70 |
Settling and allowances
Loose topsoil settles after it is spread and watered, so it is common to add 5 to 10 percent extra. If the ground is uneven or you are filling holes, allow more. It is better to have a small pile left over, which is useful for later repairs, than to run short and pay for another delivery.
Tips for buying topsoil
- Ask what the topsoil is made from. Quality varies a lot between suppliers, from screened loam to mixed fill.
- Check for stones, roots and weed seeds before it is spread over a lawn.
- Loosen the existing ground first so the new soil bonds with it rather than sitting in a separate layer.
- Weight depends heavily on moisture, so order by volume where you can.
Frequently asked questions
How much does a cubic yard of topsoil weigh? Roughly 1 to 1.3 tons, depending on moisture and composition. The calculator uses 1.1 tons as an estimate.
How many square feet does a cubic yard of topsoil cover? About 81 square feet at 4 inches deep, and 54 square feet at 6 inches.
How many bags make a cubic yard? A 1-cubic-foot bag needs 27 bags to make a cubic yard. Bagged soil is usually sold in 0.75 to 2 cubic foot sizes, so check the label.
Do I need topsoil or compost? Topsoil is a base for growing. Compost adds organic matter. Many projects use both, so ask a local garden centre for the mix that suits your plants.