Topsoil Calculator: How Much Topsoil Do I Need?
Get a clean number
Plan for .25 inches for topdressing, 2 inches for existing garden beds, and 5 inches for a new lawn.
Convert your depth into feet before calculating.
Use a topsoil calculator to find the cubic yards (topsoil is often sold this way).
Topsoil costs $15 to $30 per cubic yard.
Opt for bulk topsoil or a combo of fill dirt and topsoil to save on costs.
Whether you’re planting grass seed, filling in low spots, or prepping for a vegetable garden, topsoil is a key ingredient. But how much topsoil do you need? Use our topsoil calculator to get the right amount for your space and depth.
How Much Topsoil Is Needed For Lawn, Landscaping, and Gardening
Using the square footage of your space and the depth of topsoil required, refer to the table below to estimate how much topsoil you need. Topsoil is often sold by the cubic yard, which is equivalent to 27 cubic feet.
| Square Footage | Depth | Typical Use | Amount of Topsoil in Cubic Yards | Amount of Topsoil in Cubic Feet | Cost |
|---|---|---|---|---|---|
| 5,000 | .25 inch | Topdressing the lawn or planting grass seed | 3.90 | 105 | $59-$117 |
| 8,000 | 5 inches | New lawn | 123.5 | 3,333 | $1,853-$3,705 |
| 32 | 2 inches | Existing garden bed | .19 | 5 | $3-$6 |
| 32 | 8 inches | New garden bed | .78 | 21 | $12-$24 |
| 32 | 12 inches | New raised garden bed | 1.19 | 32 | $18-$36 |
How to Calculate Topsoil
Using the length, width, and depth of the space you’re filling, find the cubic yards of topsoil you need for your garden or lawn.
Apply the following formula to determine how much topsoil you need:
Topsoil needed (in cubic yards) = (Length x Width x Depth in feet) / 27
Example:
Length 7 feet x Width 10 feet x Depth .2 feet = 14 cubic feet
5.45 cubic feet / 27 = .52 cubic yards
How to Measure Length, Width, and Depth of Topsoil
Find the length and width of the areas you want to fill, then choose the depth based on your project.
How to Measure the Length and Width
Find the length and width of the areas you want to fill with a tape measure. Write down the numbers. Multiply the length by the width to get the square footage. Add multiple areas together, such as a small garden bed and a large one.
How to Choose Your Depth
The depth of topsoil you need depends on what you’re doing in your yard or garden. If you’re planting grass seed or a vegetable garden, you want enough topsoil to ensure healthy roots.
Here is the recommended topsoil depth by project:
Topdressing existing lawn or planting grass seed: 0.25-0.5 inch
Existing garden: 2 inches
New lawn: 4 to 6 inches
New garden bed: 8 inches
New raised garden bed: 12 inches
Custom: Measure the depth of your garden bed or project to determine depth
How to Measure Square Footage of an Irregular Space
If you have a trapezoid portion of your yard or landscaping, you must calculate the square footage slightly differently.
Identify the four sides of the trapezoidal area. Measure the length of the two parallel sides in feet, and add them together. Measure the height of the space in feet. Put the dimensions into this formula: Square footage area = ½ (Side A + Side B) x height.
How to Determine the Size of a Topsoil Bag
Topsoil is often sold by the cubic yard or cubic feet. Round up to ensure you get a big bag covering your entire area. Sometimes, topsoil is sold by weight, and you’ll need to look at the label to see how many cubic yards it covers.
Who to Hire to Fill in Topsoil
You can spread topsoil yourself with a hand tiller or rake, or hire a local landscaper to handle the job, especially if it’s an ample space. Landscapers can also plant grass seed, sod, or create a garden. The cost of a local landscaper ranges from $50 to $150 an hour, depending on the project complexity and labor costs in your area.
Frequently Asked Questions
A 40-pound bag of topsoil covers 0.76 cubic feet, enough for 4.5 square feet with a 2-inch depth or 36 square feet with a .25-inch depth, such as topdressing a standard garden bed. If you want 2 inches of fresh topsoil for your 36-square-foot garden bed, you’ll need eight 40-pound bags.
Topsoil provides plants with essential nutrients, water, and air for healthy root growth. It offers a rich ecosystem of microorganisms that improve soil quality and structure. For existing lawns, ¼ inch of topdressing can enhance root growth and support new seed. For gardens, two inches of topsoil can promote strong growth and crops.
Topsoil costs $15 to $30 per cubic yard, depending on the quality and whether you buy in bulk. Purchasing topsoil in bulk saves on cost for larger projects, such as a new lawn or large garden, but you’ll need a vehicle to transport or deliver it. To save further on costs, use fill dirt and then topsoil for your final one to three inches.
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