Topsoil Calculator
Work out how much topsoil to buy for a lawn, garden, or raised bed. Get cubic yards, tons, and bags as you type, with a weight preset for dry, typical, or wet soil.
Topsoil calculator
New lawn: 4 to 6 in settled. Raised beds: at least 6 to 12 in. Thin topdressing: 1/2 in at most.
The sizes below are an example. Type over them with your own.
Allowances
Leave blank to use 10%. Loose topsoil settles after it is spread and watered, and ground is rarely perfectly level.
Leave blank to use 1.30 tons per cubic yard (typical range 1.20 to 1.40). Use your supplier's number if you have it.
Cost (optional)
The cost is your price times the rounded amount in the result, plus delivery. Tax and minimum-order charges are not included.
- Area
- 32 sq ft
- Volume
- 32 cu ft1.19 cu yd, before the extra
- Extra
- 10%Adds 3.2 cu ft
- Order quantity
- 1.30 cu yd35.2 cu ft
- Weight
- 1.69 tonsAbout 3,400 lb, at 1.30 tons per cu yd (preset: typical topsoil)
- Bags
- 36 bags1 cu ft bag, rounded up
- Other bag sizes
- 0.75 cu ft bags: 47, 1.5 cu ft bags: 24, 2 cu ft bags: 18
How to use the topsoil calculator
- Pick the moisture level that fits your soil. It sets the weight per cubic yard, which you can override.
- Enter the length and width of each bed, lawn section, or raised bed. For a round bed, choose Circle. If you already know the square footage, choose Known area.
- Enter the depth in inches (or feet for deep beds). Use Add another area for separate beds, or Quantity for identical raised beds.
- Read the cubic yards, tons, and bag count. If you buy in bulk, order the cubic yards or tons. If you buy bags, choose the bag size printed on them.
The topsoil formula
Cubic feet = length (ft) × width (ft) × depth (in) ÷ 12
Cubic yards = cubic feet ÷ 27
Order = volume × (1 + extra % ÷ 100)
Tons = cubic yards × tons per cubic yard
Bags = cubic feet ÷ cubic feet per bag, rounded up
Worked example: an 8 ft by 4 ft raised bed, 12 inches deep
- Volume: 8 × 4 × 12 ÷ 12 = 32 cubic feet, or 1.19 cubic yards.
- Add 10% for settling: 32 cubic feet becomes 35.2. Divided by 27, that is 1.3037, shown as 1.30 cubic yards.
- Weight at 1.30 tons per cubic yard: 1.3037 × 1.30 = 1.69 tons.
- Bags of 1 cubic foot: 35.2 ÷ 1 = 35.2, rounded up to 36 bags.
How deep should topsoil be?
The right depth depends on what you are growing. These figures come from university extension services; follow your landscape plan if it calls for something different.
| Use | Depth | Source |
|---|---|---|
| New lawn, settled depth | At least 4 to 6 in | Penn State Extension |
| Raised bed or planter box | At least 6 to 12 in high | Utah State Extension |
| Adding compost to existing soil | 1 to 2 in, mixed into the top 6 in | Rutgers NJAES |
| Topdressing an existing lawn | ½ in at most at one time | Clemson HGIC |
Settled depth is the depth after the soil has been watered and has sunk, so the calculator adds 10% extra. Utah State suggests leaving the bottom open on raised beds shallower than 12 inches so roots can reach the soil below.
How much does a cubic yard of topsoil weigh?
Topsoil is heavy, and its weight changes a lot with moisture and with how much sand, clay, or compost it contains. The presets below are for loose soil as delivered. They are planning values, so replace them with your supplier's number when you have one.
| Moisture and type | Tons per cu yd | Typical range | Lb per cu ft |
|---|---|---|---|
| Dry topsoil | 1.10 | 1.00 to 1.20 | 81 |
| Typical topsoil (slightly moist) | 1.30 | 1.20 to 1.40 | 96 |
| Wet or heavy topsoil | 1.45 | 1.35 to 1.50 | 107 |
Topsoil by the bag
Bags are convenient for small beds and hard-to-reach spots. The bag count rounds up to whole bags.
| Bag size | Bags per cu yd |
|---|---|
| 0.75 cu ft | 36 |
| 1 cu ft | 27 |
| 1.5 cu ft | 18 |
| 2 cu ft | 14 (13.5 rounded up) |
Bag sizes vary by brand. Enter yours under Bag size if it is not listed.
Frequently asked questions
How many cubic yards of topsoil do I need?
Multiply the area in square feet by the depth in inches and divide by 324. A 100 sq ft bed at 4 inches deep needs 1.23 cubic yards (33.3 cubic feet). The calculator also adds 10% for settling by default, which takes that bed to 1.36 cubic yards.
How many bags of topsoil are in a cubic yard?
A cubic yard is 27 cubic feet. That is 36 bags of 0.75 cubic foot, 27 bags of 1 cubic foot, or 14 bags of 2 cubic feet (13.5, rounded up). Texas A&M AgriLife Extension publishes the same counts.
How much does a cubic yard of topsoil weigh?
Plan on about 1.30 tons (2,600 lb) for slightly moist topsoil, with a range of 1.20 to 1.40. Dry topsoil is lighter and wet or clay-heavy soil is heavier. The EPA's conversion table lists loose sandy loam at 2,392 lb per cubic yard, or 1.20 tons. Ask your supplier for the weight of the pile you are buying.
How deep should topsoil be for a lawn?
Penn State Extension says a new lawn typically needs at least 4 to 6 inches of good-quality topsoil, measured after it has firmed or settled. Because loose soil sinks as it settles, order the extra the calculator adds, or enter a higher percentage if you are spreading it over rough ground.
Is bagged topsoil the same as bulk topsoil?
Not always. A Rutgers NJAES fact sheet on raised-bed soil says many bagged products labeled potting soil, garden soil, or topsoil are exclusively organic materials. They are useful for improving garden soil, but they behave differently from mineral topsoil and usually weigh less. Check the label, and use the weight field if the product's weight is printed on the bag.
Sources
- Penn State Extension: Lawn establishment (topsoil depth)
- Utah State University Extension: Raised bed gardening
- Rutgers NJAES FS1328: Soil for raised beds
- Clemson HGIC: Topdressing a home lawn
- Texas A&M AgriLife Extension: How much compost, soil or mulch?
- U.S. EPA: Standard volume-to-weight conversion factors