Topsoil Calculator

A topsoil calculator converts the footprint of a bed, lawn, or fill area and a target depth into the volume of soil to order. Topsoil is delivered loose by the cubic yard and hauled by weight, so the result is a volume in cubic yards, cubic feet, and cubic meters, with an estimated weight in tons and a cost.

The area shape sets the formula. A rectangle is length times width. A circle uses its diameter, and its area is pi times the square of half the diameter. A triangle is half of base times perpendicular height; for a corner bed bounded by two fences at a right angle, the two fence runs are the base and the height. Each shape takes its own unit, from inches to yards or centimeters to meters, and depth has a separate unit because depth is quoted in inches while beds are measured in feet. Typical depths run 4 to 6 inches for a new lawn on bare ground or a new planting bed, the full height of a raised bed, and only 1/8 to 1/2 inch when topdressing an existing lawn, since a thicker layer smothers the grass. All numeric inputs accept decimals, fractions such as 3/4, and mixed numbers such as 5 1/2.

Every dimension is converted to feet: inches divide by 12, yards multiply by 3, meters multiply by 3.28084, and centimeters multiply by 0.0328084. Area in square feet times depth in feet gives cubic feet; dividing by 27 gives cubic yards, and multiplying by 0.0283168 gives cubic meters. Weight is cubic yards times a bulk density of 1.1 tons per cubic yard by default, which sits in the range for dry topsoil (about 2,000 to 2,300 pounds per cubic yard); saturated soil can reach 1.5 tons, which matters for truck and trailer limits. Cost is cubic yards times a price per cubic yard, $30 by default. Both defaults sit under Settings beside a step-by-step view of each conversion, and the results line states the density and price it used.

The volume is the in-place volume of a level layer at the stated depth. No settling allowance is added: loose topsoil compacts after rain and foot traffic, so a bed filled to the brim sinks below it, and delivered loads vary in moisture, which is why ordering slightly over the computed figure is common. A slope has more surface than its plan dimensions show, and low spots in a lawn take more fill than the average depth suggests.

A new lawn area of 30 by 20 feet covered 4 inches deep has an area of 600 square feet and a depth of 4 / 12 = 0.3333 feet, so the volume is 200 cubic feet. That is 200 / 27 = 7.41 cubic yards, or 5.66 cubic meters. At 1.1 tons per cubic yard the load weighs about 8.15 tons, and at $30 per cubic yard it costs $222.22.

Topsoil volume estimation applies across residential landscaping, commercial groundskeeping, and agricultural preparation. Knowing the amount before ordering prevents costly over-delivery fees and avoids project delays from shortfalls.

• Raised Garden Beds: Measure the interior length, width, and depth of a raised bed before ordering a topsoil-compost blend from a landscape supply yard. A 4 x 8 foot bed filled 12 inches deep holds 32 cubic feet, about 1.19 cubic yards.
• Lawn Renovation: Topdressing after core aeration spreads a quarter inch or less over the whole lawn. 2,000 square feet at 1/4 inch is 41.7 cubic feet, about 1.54 cubic yards, a small fraction of the 4 to 6 inches a new lawn on bare ground needs.
• Tree Ring Planting: The planting area around a new tree is a circle. A ring 6 feet across filled 4 inches deep beneath the mulch layer takes 9.42 cubic feet, about 0.35 cubic yards.
• Corner Flower Beds: A wedge-shaped bed in a yard corner is a right triangle whose two fence-side lengths are its base and height, so a bed running 10 feet along one fence and 8 feet along the other covers 40 square feet without any manual triangle math.
• Contractor Bidding: Landscape professionals can run several shape calculations in sequence, adjusting the price per cubic yard to match local supplier pricing, and turn the results into material cost line items for project proposals.
• Community Garden Plots: Coordinators planning a grid of identical raised beds can calculate one bed and multiply by the plot count to estimate the total bulk order, using the weight per cubic yard for truck capacity planning.
• Erosion Repair: Rebuilding a washed-out slope section takes the surface dimensions of the damaged area at the required fill depth, plus a margin for settling before reseeding.