How to use the topsoil calculator
Enter the area you're covering and how deep you want the new soil. The result is the volume to order, with a settling allowance added, because loose soil compacts as it gets watered and walked on. Bulk topsoil is sold by the cubic yard almost everywhere; the tons figure is there for suppliers that weigh loads, and to check that your truck or trailer can carry it.
The formula
cubic feet = area (ft²) × depth (ft) × (1 + settling %)
cubic yards = cubic feet ÷ 27
tons = cubic yards × density
Worked example: a 30 × 40 ft lawn, 4 inches of topsoil
- Area: 30 × 40 = 1,200 ft².
- Volume: 1,200 × (4 ÷ 12) = 400 ft³.
- Add 10% for settling: 400 × 1.10 = 440 ft³, or 440 ÷ 27 = 16.3 yd³.
- Weight of dry topsoil at 1.1 tons per yard: 16.3 × 1.1 = 17.9 tons.
That's a full tri-axle dump truck or two smaller loads. In 0.75 ft³ bags it would be 587 bags, which is why the calculator suggests bulk once a job goes past a yard or so.
How deep should topsoil be?
| Job | Depth of new soil |
|---|---|
| Topdressing or overseeding a lawn | ¼-½ in, raked in |
| Filling low spots | Up to 2 in at a time, then let grass grow through |
| New lawn from seed or sod | 4-6 in |
| Vegetable or flower bed | 6-12 in |
| Raised bed | The bed height, usually with compost mixed in |
When filling low spots in an existing lawn, more than about 2 inches at once will smother the grass. Build up deeper hollows over a few sessions.
Buying topsoil
- Ask if it's screened. Screened topsoil has had rocks, roots and clods removed. It spreads far more easily and is worth the small extra cost.
- Ask what's in it. "Topsoil" isn't a regulated term. Some yards sell straight field soil, others a blend with compost or sand. A blend is better for beds; plain screened soil is fine under sod.
- See it before you buy if you can. Squeeze a damp handful. It should crumble apart, not form a sticky ribbon like clay.
- Check the weight limit. A single cubic yard of dry topsoil weighs over a ton, which is more than many half-ton pickups are rated to carry. Check your payload rating, and remember wet soil is heavier still.
Common mistakes
- Burying the existing soil with a hard line. Rough up or till the top inch or two of the old ground first so the layers blend and water drains through.
- Spreading wet soil. Working soil when it's soaked destroys its structure. Wait for a dry spell.
- Forgetting the grade. New soil should slope away from your house foundation, not toward it.
Questions people ask
How much topsoil do I need for a new lawn?
Plan on 4 to 6 inches of good topsoil for seed or sod. At 4 inches that's about 1.23 cubic yards per 100 square feet, or 12.3 yards per 1,000 square feet, before any allowance for settling.
How much does a yard of topsoil weigh?
Dry, screened topsoil weighs about 1 to 1.15 tons per cubic yard. Damp topsoil is heavier, around 1.2 to 1.35 tons. Rain on an open truckload can add a lot of weight.
How many bags of topsoil equal a yard?
27 cubic feet make a yard, so you need 36 bags of 0.75 cubic feet, 27 bags of 1 cubic foot, or 18 bags of 1.5 cubic feet. Past about a yard, bulk delivery is almost always cheaper.
How much area does a yard of topsoil cover?
One cubic yard covers 324 square feet at 1 inch, 81 square feet at 4 inches and 54 square feet at 6 inches.
Why does topsoil settle?
Loose soil has a lot of air in it. Watering, rain and foot traffic pack it down, often by 10 to 20% in the first season. Order a little extra, or plan a light top-up after the first few weeks.
Sources and assumptions
- Supplier and equipment density charts (e.g. the Caterpillar Performance Handbook): loose topsoil about 1.0-1.15 tons/yd³ dry, 1.2-1.35 damp. Ask your supplier for theirs.
- Settling allowance of 10% is a rule of thumb; heavy clay and very loose screened soils can settle more.
Last reviewed 26 October 2026. Every formula on this page is checked against the worked example above in our automated tests. Found a problem? Tell us.