Topsoil Calculator

How to calculate how much topsoil you need

Topsoil is ordered by volume, in cubic yards. Multiply the area in square feet by the depth in feet to get cubic feet, then divide by 27, because a cubic yard is 27 cubic feet. If you measure the depth in inches, the shortcut is square feet × inches ÷ 324. The 324 is 27 × 12.

For example, one cubic yard covers 81 square feet at 4 inches deep. For other depths, see the coverage table in the mulch calculator.

For a circle, measure the diameter. The area is π × (diameter ÷ 2)². If your area is an odd shape, split it into rectangles and circles and add one area for each piece. Each area has its own depth, so a lawn and a raised bed can go in the same calculation.

Example: a new lawn of 500 square feet

You are seeding a lawn of 500 square feet (25 ft by 20 ft) and want 4 inches of firmed topsoil. You add 15% for settling and your supplier says the soil weighs 2,200 pounds per cubic yard. The 15% is only an example, not a recommendation.

How deep should topsoil be?

These are the depths the calculator offers in the “Suggested depth” menu. They come from university extension publications (checked October 2026). Your own soil test and your plants come first.

Topsoil settles, so order a little more

Loose topsoil loses volume once it is watered and walked on. The lawn depths above are given after the soil is firmed, so the depth you spread has to be greater. New Mexico State University advises settling the area with about 0.5 to 1 inch of irrigation water before fine grading (guide H-509).

How much extra is not standardized. CalculatorSoup suggests typically 10 to 20 percent extra, while Custom Topsoil says that a third of topsoil will settle. Those two figures are far apart, so ask your supplier and type the percentage in the “Extra for settling” box. The calculator adds it to the volume, the weight and the bags.

How much does topsoil weigh?

Some suppliers quote by the ton, so the calculator also gives the weight. It uses the short ton of 2,000 pounds. The weight of topsoil changes a lot with moisture, texture and organic matter, so pick the value closest to your supplier's figure or type your own.

As a cross-check, Penn State Extension uses a soil bulk density of 1.33 grams per cubic centimeter for a silt loam (source). Converted, that is about 2,240 pounds per cubic yard for undisturbed soil. Bulk topsoil from a yard is a different material, so do not use it in place of your supplier's figure.

With 2,200 pounds per cubic yard, one ton of topsoil covers about:

Bagged topsoil: how many bags?

Bags are sold by volume in cubic feet, and the number is printed on the label. The calculator divides the cubic feet you need by the bag size and rounds up. A bag of 0.75 cubic feet, such as Scotts Premium Topsoil, means 36 bags per cubic yard (27 ÷ 0.75). A 1 cubic foot bag means 27 bags per cubic yard. The 1 cubic foot option comes from an in-ground garden soil product, since no topsoil bag of that size could be checked.

The Scotts page states 4 square feet at 2 inches, a little less than the 4.5 from the geometry. Bag weights differ between products, so go by the volume on the label.

Frequently asked questions