Topsoil Calculator: How Much Topsoil Do I Need?

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To figure out how much topsoil you need, use the topsoil calculator below or multiply the area's length by its width in feet, multiply by the depth in inches, and divide by 12 to get cubic feet. Divide that by 27 for cubic yards. One cubic yard spreads about 81 square feet at 4 inches deep or 162 square feet at 2 inches, and a new lawn typically needs at least 4 to 6 inches of settled topsoil.

Enter your area and depth below. The calculator gives cubic yards for a bulk order and bag counts for smaller jobs.

How much topsoil do you need?

Enter the area size and depth. Results in cubic yards and bags.

ft
ft
in

Loose topsoil settles; add 10 to 20 percent if you will compact it or are filling low spots. Bulk topsoil is sold by the cubic yard (27 cu ft).

How to measure for topsoil

  1. Map the area. Measure the length and width in feet. For an irregular yard, split it into rectangles and triangles, work out each area, and add them. Leave out driveways, patios, and planting beds that won't get topsoil.
  2. Decide on the finished depth. Use the depth table below. For a new lawn, remember that turf specialists state their numbers as a firmed or settled depth, not a loose one.
  3. Measure low spots separately. For a dip or a rut, lay a straight board across it and measure down to the soil at several points. Average those readings and use that as the depth for that patch only.
  4. Check the grade near the house. Penn State Extension recommends that lawn areas slope away from foundations at 1 to 4 percent, which is a drop of 1 to 4 feet over 100 feet. If you need to build up soil near the house to get that slope, measure the extra depth there.
  5. Enter one area at a time if depths differ, then add the results.

The topsoil formula

The calculator uses:

  • Cubic feet = length (ft) × width (ft) × depth (in) ÷ 12
  • Cubic yards = cubic feet ÷ 27
  • 0.75 cu ft bags = cubic feet ÷ 0.75, rounded up
  • 1 cu ft bags = cubic feet, rounded up

Dividing by 12 converts inches to feet, and a cubic yard is 27 cubic feet (3 × 3 × 3).

Worked example (the calculator's default values)

An area 20 ft long and 10 ft wide, covered 4 inches deep:

  1. Area: 20 × 10 = 200 sq ft
  2. Volume: 200 × 4 ÷ 12 = 66.7 cu ft
  3. Cubic yards: 66.7 ÷ 27 = 2.47 cubic yards
  4. 0.75 cu ft bags: 66.7 ÷ 0.75 = 88.9, rounded up to 89 bags
  5. 1 cu ft bags: 66.7, rounded up to 67 bags

The calculator shows: "You need 2.47 cubic yards of topsoil (66.7 cu ft). That is 89 bags of 0.75 cu ft or 67 bags of 1 cu ft."

Eighty-nine bags is a lot of lifting. At this size, a bulk delivery by the cubic yard is usually the practical choice. If you plan to firm or roll the soil, add 10 to 20 percent as the calculator note suggests. For this example, that raises the order to roughly 2.72 to 2.96 cubic yards.

A second example: patching a low spot

Small jobs work the same way. Say a sunken patch is about 6 ft by 4 ft and your straightedge readings average 2 inches deep. That is 24 sq ft × 2 ÷ 12 = 4 cu ft, or 4 ÷ 0.75 = 5.3, so buy 6 bags of 0.75 cu ft. Fill it in two passes, water to settle, and top off any spot that sinks below the surrounding lawn.

Topsoil: area times depthPlan of a 20 by 10 foot area and a cross-section showing a new 4 inch layer of topsoil over the existing ground. 20 times 10 is 200 sq ft; times 4 inches divided by 12 is 66.7 cubic feet; divided by 27 that is 2.47 cubic yards, or 89 bags of 0.75 cu ft or 67 bags of 1 cu ft.AREA × DEPTH20 ft10 ftCross-sectionnew topsoilexisting ground4 in200 sq ft20 ft × 10 ft66.7 cu ft200 sq ft × 4 in ÷ 122.47 cu yd66.7 cu ft ÷ 272.47 cu yd66.7 cu ft of topsoilIn bags: 89 of 0.75 cu ftor 67 of 1 cu ft
Multiply area by depth: 200 sq ft x 4 in / 12 = 66.7 cu ft, which divided by 27 is 2.47 cubic yards.

How deep should topsoil be?

The right depth depends on the job. Here is what extension services and product labels recommend:

ProjectTopsoil depthSource
Covering grass seed on a bare patchAbout 1/4 in over the seedExtension Master Gardener (Ask Extension)
Leveling a lawn before overseeding1 to 2 in, mixed into the top 1 to 2 in of native soilScotts Premium Topsoil label
New garden bed on existing ground2 to 3 in, mixed into the top 6 to 8 in of native soilScotts Premium Topsoil label
New lawn from seed or sodAt least 4 to 6 in, firmed or settledPenn State Extension
New lawn, ideal6 to 8 inTexas A&M AgriLife

For raised beds, the math and the soil blend are different; see our raised bed soil guide.

Topsoil per 1,000 square feet

Big lawns are easier to plan in chunks of 1,000 sq ft. Multiply the figure below by your total square footage divided by 1,000.

DepthCubic yards per 1,000 sq ftCubic feet per 1,000 sq ft
1/4 in0.7720.8
1/2 in1.5441.7
1 in3.0983.3
2 in6.17166.7
3 in9.26250.0
4 in12.35333.3
6 in18.52500.0

Example: a 3,500 sq ft lawn area at 4 inches needs 3.5 × 12.35 = about 43.2 cubic yards before any allowance for settling.

Bags vs. bulk

Bagged topsoil is handy for patching and small beds. The common bag is 0.75 cu ft; Scotts Premium Topsoil comes in that size, and the Earthgro 40 lb bag is rated to cover 4.5 sq ft at 2 inches deep, which works out to the same 0.75 cu ft. It takes 36 of those bags to make one cubic yard.

Beyond a cubic yard or two, bulk is far less work. When you call a supplier, ask whether the soil is screened, what it contains, and what increments they deliver in. UConn Extension's topsoil buying guide notes that most screened topsoil passes through a 3/4 inch mesh, and that unscreened soil is rarely worth the savings once you count the time spent removing rocks and debris. The same guide estimates about 12 cubic yards per 1,000 sq ft at 4 inches deep, which matches the chart above.

It also helps to know what "topsoil" means on a label. University of Maryland Extension points out that true topsoil is mineral soil made of clay, silt, and sand, and that bagged "organic soil" products typically contain none of it. Scotts sells its Premium Topsoil as a lawn and garden soil conditioner that adds peat moss and organic matter to existing soil. Read the bag so you know whether you are buying mineral soil or an amendment.

Tips for spreading topsoil

  • Mix the first layer in. Both Scotts' label directions and extension guidance favor working new soil into the native soil instead of leaving a distinct layer on top. Iowa State Extension notes that distinct soil layers impede water movement and discourage root growth.
  • Spread in passes. Dump piles across the area, rake to about half the target depth, then add the rest. It is easier to hit an even grade in two passes.
  • Firm before you measure. Water or roll the soil lightly, then check depth again. Fill any spots that sank.
  • Keep the slope going the right way. Aim for the 1 to 4 percent fall away from the house that Penn State Extension recommends.
  • Test the soil. For a new lawn, Penn State Extension suggests a soil test from a university or private lab three to four weeks before you prepare the ground.

Common mistakes to avoid

  • Ordering to a loose depth when you need a settled depth. Lawn specs are firmed depths. Add extra for settling.
  • Using one depth for the whole yard. Low spots, slopes, and new beds each need their own number.
  • Forgetting the hardscape. Subtract driveways and patios before you calculate.
  • Mixing inches and feet. The depth field is in inches. Entering 0.33 (a third of a foot) gives a result twelve times too small.
  • Burying seed. When covering new seed, a thin layer is enough; the Ask Extension answer suggests about 1/4 inch.

Frequently asked questions

How much area does a yard of topsoil cover?

About 81 square feet at 4 inches deep, 162 square feet at 2 inches, and 324 square feet at 1 inch.

How many bags of topsoil make a yard?

A cubic yard is 27 cubic feet, so it takes 36 bags of 0.75 cu ft or 27 bags of 1 cu ft.

How much topsoil do I need for a new lawn?

Penn State Extension recommends at least 4 to 6 inches of good topsoil, measured after it is firmed or settled. Texas A&M AgriLife calls 4 inches the minimum and 6 to 8 inches desirable. For 1,000 sq ft at 4 inches, that is about 12.35 cubic yards before a settling allowance.

Should I add extra topsoil for settling?

Yes, if you will compact it or you are filling low spots. The calculator note suggests adding 10 to 20 percent to the volume it shows.

Is topsoil the same as garden soil?

No. Topsoil is mineral soil (clay, silt, and sand). Bagged garden soils and "organic" soils are usually blends heavy in compost, bark, or wood products. Use topsoil to build grade and garden soil to amend beds.