How Much Topsoil Do I Need?

The amount of topsoil you need depends on the size of the area you're covering and the depth of topsoil required. Measure the length and width of the project area, determine the desired depth, and convert that volume into cubic yards. For irregular areas, divide the project into smaller measurable sections and calculate each separately.

The easiest option is to enter your measurements into the Soils.com Topsoil Calculator, which estimates the amount of topsoil required based on your project dimensions.

This guide walks through how the calculation works, how depth changes the total quantity, and what to consider before you order.

How Do You Calculate How Much Topsoil You Need?

The basic process has five steps:

1. Measure the length of the area.
2. Measure the width of the area.
3. Determine the desired depth.
4. Calculate the volume: Length × Width × Depth = Volume
5. Convert the result to cubic yards.

The key is keeping your units consistent before you convert — depth is usually measured in inches, while length and width are usually measured in feet, so you'll need to convert depth to feet before multiplying.

Example: A 20 ft × 30 ft area works out to 600 sq. ft. Multiply that by your intended depth (converted to feet) to get your volume in cubic feet, then convert to cubic yards.

Why Topsoil Depth Matters

Depth has an outsized effect on total volume — doubling the depth doubles the volume required for the same surface area. It's a detail that's easy to underestimate when you're focused on square footage.

Here's what that looks like for a 1,000-square-foot area at a few common depths:

These are volume estimates, not guaranteed order quantities — actual needs can shift based on site conditions. The right depth also depends on the application: a thin topdressing calls for far less material than establishing an entirely new growing layer. For guidance on choosing a depth for your specific project, see our guide on how deep topsoil should be.

How Much Topsoil Do You Need for Different Projects?

The amount of topsoil you need varies considerably by application. Understanding what topsoil is and how it is used can also help you determine whether it is the right material for the project before calculating quantity.

Existing Lawns

Topdressing, minor leveling, and improving shallow areas typically require a thin application — considerably less material than establishing an entirely new growing layer.

New Lawns and Sod

Quantity here depends on how much suitable growing soil already exists on-site and how much additional depth needs to be added before grass or sod can establish.

Gardens and Planting Beds

These projects may call for deeper soil layers than a surface lawn application, depending on what's being planted, the existing soil, and how the bed is constructed.

Finish Grading

Topsoil often forms the final growing layer after the underlying elevation has already been established with another material — which is where fill dirt frequently comes into the picture.

How Many Cubic Yards of Topsoil Do I Need?

Bulk topsoil is commonly measured and ordered by volume, with cubic yards frequently used to estimate the amount needed for a project. One cubic yard equals 27 cubic feet. You can also use our Cubic Yard Calculator to estimate project volume from your measurements.

If your dimensions are measured in feet, the formula is:

Length × Width × Depth (in feet) ÷ 27 = Cubic Yards

Example: For 600 square feet at 3 inches deep:

• 3 inches = 0.25 feet
• 600 × 0.25 = 150 cubic feet
• 150 ÷ 27 ≈ 5.6 cubic yards

If you'd rather skip the manual conversion, the Topsoil Calculator handles this math automatically based on your project dimensions.

How Do You Measure Irregular Areas for Topsoil?

Most lawns and landscape beds aren't perfect rectangles. For irregularly shaped areas:

1. Divide the space into smaller rectangles or other simple shapes.
2. Measure each section individually.
3. Calculate the area of each section separately.
4. Add the areas together for a total square footage.
5. Apply your intended depth to get the total volume.

For highly irregular shapes, treat the result as a reasonable approximation rather than an exact figure.

Should You Order Extra Topsoil?

Possibly — but there's no universal rule that fits every project. Calculated volume and actual project requirements can differ because of uneven ground, grade variations, measurement error, settling, site conditions, how the material is spread, and changes made during installation. Some projects may benefit from allowing for additional material, but how much extra makes sense depends on the specifics of your project and how precise your measurements are.

Does Topsoil Settle After It Is Spread?

Loose bulk material can settle after it's placed and spread, so the finished depth can end up somewhat different from the initial loose placement. How much this matters depends on the material's characteristics, moisture content, how it's handled, site preparation, and the intended application — there's no single compaction percentage that applies across the board. It's one reason calculator estimates are best treated as a planning tool rather than a guarantee.

What If You Need to Raise the Ground Significantly?

If your project requires substantial elevation changes, don't automatically calculate the entire required depth as topsoil. For example, if you need to raise a large area significantly before establishing a lawn, fill dirt is often more appropriate for building the underlying grade, with topsoil added on top as the growing layer. For more on how these materials work together, see our guide to topsoil vs. fill dirt.

How to Estimate Topsoil Before Ordering

1. Measure the project area
2. Determine the intended topsoil depth
3. Calculate cubic-yard volume
4. Account for site conditions and project variables
5. Confirm the material is appropriate for the application
6. Check delivered pricing and availability

Frequently Asked Questions About Topsoil Quantity

How many square feet does one cubic yard of topsoil cover?

It depends entirely on depth. One cubic yard covers a larger area when spread thinly and a smaller area when applied more deeply. Use the Topsoil Calculator to determine coverage based on your intended depth.

How many cubic yards of topsoil do I need for 1,000 square feet?

It depends on depth. Approximately: 1 inch → 3.1 cubic yards, 2 inches → 6.2 cubic yards, 3 inches → 9.3 cubic yards, 4 inches → 12.3 cubic yards, 6 inches → 18.5 cubic yards. These are volume calculations rather than guaranteed order quantities.

How deep should topsoil be?

There isn't one universal depth. The appropriate depth depends on whether you're working with an existing lawn, establishing sod, building a planting bed, or completing another landscaping project, as well as the condition of the existing soil.

Should I round up when ordering topsoil?

Calculated volume is an estimate, and real projects can be affected by uneven ground, settling, measurement differences, and site conditions. Whether additional material is appropriate depends on the project and how precise the measurements are.

Can I use fill dirt underneath topsoil?

Yes, depending on the project. Fill dirt may be used to establish underlying grade or fill substantial depth, while topsoil can provide the final growing layer for grass or landscaping.