How to use
- Enter the length and width, or switch to "I know the area" and type it in.
- Pick what the soil is for. The calculator fills in a typical depth, which you can change.
- Keep the 10% settling allowance or change it, then select "Calculate".
How deep should topsoil be?
| Project | Depth | Guidance |
|---|---|---|
| New lawn from seed or sod | 4 to 6 inches, settled | Penn State Extension: "a minimum of 4 to 6 inches (firmed or settled depth) of a good-quality topsoil." University of Illinois Extension suggests six inches or more of well-prepared soil. |
| Garden bed on existing soil | About 8 inches | Oregon State Extension: a soil and organic mix about 8 inches deep is enough for most vegetables. The University of Maryland suggests at least 8 inches of a compost and topsoil mix over compacted or poor soil. |
| Raised bed on a hard surface | 8 to 24 inches | University of Maryland: at least 8 inches for leafy greens, beans, and cucumbers; 12 to 24 inches for peppers, tomatoes, and squash. |
These depths are measured after the soil has settled. That's why the calculator adds an allowance on top.
A quick check on the math
Purdue Extension notes that about 19 cubic yards of topsoil makes a layer 6 inches deep over 1,000 square feet. The calculator gives 18.52 cubic yards for the same job before any extra (1,000 × 0.5 ÷ 27), so Purdue's figure is that number rounded up.
Example: a new lawn 40 ft by 25 ft (1,000 square feet) at 4 inches is 333.3 cubic feet, or 12.35 cubic yards. With 10% for settling, order about 13.58 cubic yards.
How much does topsoil weigh?
The USDA Natural Resources Conservation Service gives about 1.33 grams per cubic centimeter as the bulk density of a typical medium-textured soil. That works out to roughly 1.12 tons per cubic yard of dry soil, which is the calculator's default. Delivered topsoil is usually damp, and water adds weight, so a truckload can weigh noticeably more. If your supplier gives a weight per yard, open "Soil weight" and enter it. Weight matters most when you're hauling it yourself or checking what a truck or trailer can carry.
Bagged or bulk topsoil?
A cubic yard is 27 cubic feet, so it takes 36 bags of 0.75 cubic feet to make one. A common 0.75 cubic foot bag covers only about 4 square feet at 2 inches deep, according to the retailer's listing for Scotts Premium Topsoil. Bags work for patching a few spots or topping up a planter. For a new lawn or a big bed, bulk delivery is far cheaper per yard.
Buying tips
- Ask whether the topsoil is screened. Screened soil has rocks and roots removed and spreads much more easily.
- Ask what it's made of. "Topsoil" can mean anything from native field soil to a blend with compost.
- Have the truck dump as close to the work area as it safely can. Moving 10 or more yards by wheelbarrow is a full day's work.
- Don't fill raised beds with straight topsoil. Use a blend made for beds, as described above.
- If you can, test your existing soil first. Your local extension office can tell you how.
Common mistakes
- Forgetting settling. Loose soil settles after watering and foot traffic. The 10% default is a planning allowance, not a standard; use more for very fluffy soil.
- Burying the house. The University of Missouri Extension advises keeping the finished grade at least 3 inches below the top of the foundation on basement homes. Check before you raise the grade along a wall.
- Entering depth in feet. Six inches is 6, not 0.5.
Sources
Lawn depth: Penn State Extension, Lawn Establishment; University of Illinois Extension, Preparing Lawn Soil and Site. Volume check: Purdue Extension AY-28-W. Garden and raised beds: Oregon State Extension FS 270; University of Maryland Extension, Soil to Fill Raised Beds. Soil density: USDA NRCS Soil Quality Indicators, Bulk Density. Foundation grade: University of Missouri Extension EQ500. Bag size: Scotts Premium Topsoil, 0.75 cu ft.
Related calculators
- Mulch Calculator - how much mulch to put on top of your beds
- Gravel Calculator - cubic yards and tons of gravel
- Retaining Wall Calculator - build up a raised area with a block wall
- Percentage Calculator - work out a different extra percentage
Frequently asked questions
How many square feet does a yard of topsoil cover?
At 4 inches deep, one cubic yard covers 81 square feet. At 6 inches it covers 54 square feet. Divide 324 by the depth in inches to get the coverage.
How much topsoil do I need for a new lawn?
Penn State Extension recommends at least 4 to 6 inches of settled topsoil. For 1,000 square feet at 6 inches, that's about 18.5 cubic yards before any allowance for settling.
Can I fill a raised bed with topsoil?
Extension services usually recommend a blend instead. The University of Maryland suggests equal parts compost and soilless mix, with topsoil no more than 20% of the mix in beds at least 16 inches deep.
How much does a cubic yard of topsoil weigh?
Dry soil of a typical texture weighs roughly 1.1 tons per cubic yard, based on USDA NRCS bulk density figures. Moist topsoil from a supplier can weigh more.
How many bags of topsoil equal a yard?
36 bags of 0.75 cubic feet, 27 bags of 1 cubic foot, 18 bags of 1.5 cubic feet, or 13.5 bags of 2 cubic feet make one cubic yard.