Topsoil Calculator
How much topsoil to buy for a lawn, a garden bed, or a thin top dressing, counting the settling after you spread it.
Why our numbers are more realistic
Some topsoil calculators make settling optional or leave it to you. Loose soil settles, so we read new-lawn guidance as the settled depth. Here's what changes:
| Typical calculator | This calculator | Why it matters |
|---|---|---|
| Leaves settling optional, or up to you | Treats it as settled depth and adds 15% for settling on lawns, beds and leveling | Loose soil settles after it's spread and watered, so ordering the exact volume leaves you short of the depth you wanted. A 1,000 sq ft lawn at 5 in needs about 17.8 cubic yards here, against 15.4 with no allowance. |
| One depth field, often a lawn depth for every job | Starts from the job: 5 in for a new lawn, ¼ in for top dressing, 10 in for a bed, ½ in for leveling | Each job needs a very different depth. University guidance (via a city lawn guide) calls for 4 to 6 in of topsoil for a new lawn. Older university guidance puts top dressing at ¼ in, and says as much as ½ in can go on without smothering the grass. A lawn depth used for top dressing would order 20 times too much. |
| One guide's "18 bags" per cubic yard is a different bag size | Bag counts for 1 cu ft and 0.75 cu ft bags, plus bulk yards and tons | Bag counts only mean something for one bag size. A cubic yard is 27 bags of 1 cu ft but 36 bags of 0.75 cu ft; "18 bags" implies a 1.5 cu ft bag, so check the size on the bag. |
How this works
Cubic feet = area × settled depth (in inches ÷ 12) × 1.15 for settling. Cubic yards = cubic feet ÷ 27. Bags = cubic feet ÷ bag size, rounded up. Tons = cubic yards × 1.1.
- New lawn, seed or sod: 5 in, the middle of the 4 to 6 in range. Sod needs the same soil as seed: it comes with too little soil of its own to sustain it.
- Top dressing: ¼ in, with a warning above ½ in, since too much smothers grass. No settling allowance; it's too thin to settle much. 1,000 sq ft at ¼ in is about 0.77 cubic yards.
- Raised bed or garden: 10 in, the middle of the 8 to 12 in range often used (trade sources only).
- Leveling: ½ in at a time, up to 1 in (our guidance). Fill deeper low spots in layers.
- Settling: 15%. Spread soil settles once it's watered and walked on, but no agency publishes a standard figure. Estimates from soil-density and earthwork figures run about 10% to 25%, with sandy soil settling less and clay more, so we use 15% as a planning allowance. Top dressing gets none.
- Weight: 1.1 tons per cubic yard for screened, moist topsoil, in a 0.9 to 1.4 range. Moisture changes it a lot.
Common questions
How many bags of topsoil are in a cubic yard?
27 bags of 1 cu ft, or 36 of 0.75 cu ft. With our 15% for settling, a cubic yard of settled soil takes about 31 bags of 1 cu ft. From about 2 cubic yards up, bulk delivery is usually cheaper (our estimate), and your results will say so.
How deep should topsoil be for a new lawn?
4 to 6 in of quality topsoil, for seed or sod, per university guidance. We use 5 in as the settled depth. If your soil is decent, 4 in may do; pick "My own depth" and enter 4.
How much topsoil to top dress a lawn?
About ¼ in. Older university guidance says up to ½ in can go down without smothering the grass. For more, spread it in passes and let the grass grow through each one.
How many tons is a cubic yard of topsoil?
About 1.1 tons for screened, moist topsoil, though figures we found run from 0.9 to 1.4. If your supplier sells by the ton, ask for their figure.
What this doesn't cover
- Compost and other amendments, and soil testing. Many raised beds use a topsoil and compost mix, so check what you plan to buy.
- Blending topsoil into the subsoil below it, which affects how deep to prepare but not how much to buy.
- Slopes and very uneven ground. Measure the average depth.
Sources
- Mississippi State University Extension, "Sod Installation and Maintenance": sod "is not sold with enough topsoil to sustain it"; prepare the soil before delivery.
- Iowa DOT, special provision SP-155079 (topsoil): spread topsoil settles; 6 in under sod.
- Hampton Roads regional specifications, Section 602 (topsoil): settlement after placement, left to the contractor to correct.
- Ask Extension, leveling a lawn: match the top dressing to the soil below; sand only over sandy soil; don't bury the grass.
- Purdue Extension AY-28-W, Establishing a Lawn from Sod: control weeds before planting; layers of unlike soil slow water and roots.
- City of Charlottesville, "Healthy Lawns," citing Virginia Cooperative Extension: 4 to 6 in of quality topsoil for a lawn.
- Michigan State University Extension bulletin archive, lawn topdressing: older guidance of ¼ in, up to ½ in; about one cubic yard per 1,000 sq ft at ¼ in (we calculate 0.77).
- Retail bag listings for 1 cu ft and 2 cu ft topsoil: coverage at 2 in depth, used to check bag sizes.
- Supplier and trade weight figures: 0.9 to 1.4 tons per cubic yard. These are not standards, so we show a range.
Numbers last reviewed: October 4, 2026.