Topsoil calculator
This topsoil calculator works out how much soil you need for a lawn, a garden bed or a set of raised beds, in cubic yards for bulk delivery, cubic feet, bags of any size and approximate tons.
- Rectangle, circle or raised beds (with a bed count)
- Cubic yards, cubic feet and bags of any size
- Tons from an editable weight, plus bulk vs bag cost
Last updated
How to use the topsoil calculator
- Choose the area: a rectangle or circle for a lawn or garden bed, or raised beds if you are filling several boxes of the same size.
- Enter the length and width (or diameter) in feet, and how deep the soil should be in inches. For raised beds, enter one bed’s inside size and the number of beds.
- Pick the bag size printed on the bags you plan to buy, and add a few percent extra if you want a margin for settling.
- Read the cubic yards for bulk delivery, the bag count and the approximate tons. Add prices to compare bulk with bags.
How to calculate topsoil
Multiply the area by the depth in feet to get cubic feet, then divide by 27 for cubic yards, the unit bulk soil is sold in.
cubic yards = length (ft) × width (ft) × depth (in ÷ 12) ÷ 27
For a round area, the area is 3.1416 × (diameter ÷ 2)². For raised beds, multiply one bed’s volume by the number of beds. For bags, divide the cubic feet by the bag size and round up. For tons, multiply cubic yards by your supplier’s weight per yard:
bags = cubic feet ÷ bag size, rounded up
tons = cubic yards × tons per cubic yard
The weight box starts at 1 ton per cubic yard as a placeholder, not a measured figure. Soil weight depends on its mix and how wet it is, so replace it with the number your supplier gives you.
Worked example
A 20 × 10 ft area for a new lawn, covered with 4 inches of topsoil, bought in 0.75 cubic foot bags.
- Area: 20 × 10 = 200 square feet.
- Volume: 200 × (4 ÷ 12) = 66.7 cubic feet.
- Cubic yards: 66.7 ÷ 27 = 2.47 cubic yards.
- Bags: 66.7 ÷ 0.75 = 88.9, so 89 bags of 0.75 cu ft.
- Weight: at a placeholder 1 ton per yard, about 2.47 tons.
For bulk, most suppliers sell by the half or whole yard, so you would order 2.5 yards. Eighty-nine bags is a lot of lifting, which is why bulk delivery usually wins for lawn jobs.
How deep should topsoil be?
For a new lawn, Penn State Extension says a minimum of 4 to 6 inches of good topsoil, measured after it has been firmed or settled, is typically needed. For raised beds, University of Maryland Extension recommends at least 8 inches of soil for leafy greens, beans and cucumbers and 12 to 24 inches for peppers, tomatoes and squash when the beds sit on a hard surface (both last checked 6 November 2026).
| Project | Depth | Source |
|---|---|---|
| New lawn | 4 to 6 in of settled topsoil, minimum; ideally mix 2 in of it into the top 2 to 3 in of subsoil | Penn State Extension |
| New garden bed over poor or compacted soil | At least 8 in of a compost and topsoil mix spread on top | UMD Extension |
| Raised bed on a hard surface: greens, beans, cucumbers | At least 8 in | UMD Extension |
| Raised bed on a hard surface: peppers, tomatoes, squash | 12 to 24 in | UMD Extension |
Since Penn State gives the lawn depth as settled, loose soil from the truck should go on a little deeper than the finished depth you want.
How many bags of soil make a cubic yard?
One cubic yard is 27 cubic feet, so it takes 27 bags of 1 cubic foot, 36 bags of 0.75 cubic feet, 18 bags of 1.5 cubic feet or 13.5 bags of 2 cubic feet. Bags are sold by volume or by weight; when a bag lists only pounds, look for the cubic feet in the fine print, because weight changes with moisture.
| Bag size | Bags per cubic yard | Sq ft per bag at 1 in | Sq ft per bag at 2 in | Sq ft per bag at 4 in |
|---|---|---|---|---|
| 0.75 cu ft | 36 | 9 | 4.5 | 2.25 |
| 1 cu ft | 27 | 12 | 6 | 3 |
| 1.5 cu ft | 18 | 18 | 9 | 4.5 |
| 2 cu ft | 13.5 | 24 | 12 | 6 |
For a raised bed mix, UMD Extension suggests compost and purchased topsoil in a 1:2 or 1:1 ratio. Work out the total here, then split it: for 1:2, one third compost and two thirds topsoil.
Common questions
How do I calculate how much topsoil I will need?
Multiply length × width in feet by the depth in inches ÷ 12 to get cubic feet, then divide by 27 for cubic yards. A 20 × 10 ft area at 4 inches deep is 200 × 0.333 = 66.7 cubic feet, or 2.47 cubic yards.
How much will a 40 lb bag of topsoil cover?
It depends on the bag’s volume, not its weight, so check the cubic feet printed on it. A 0.75 cubic foot bag covers 9 square feet at 1 inch deep or 4.5 square feet at 2 inches; Scotts rates its 0.75 cu ft Premium Topsoil at 4 square feet at 2 inches.
How much area will 1 ton of topsoil cover?
Divide 1 ton by your supplier’s weight per cubic yard. If their soil weighs 1 ton per yard, a ton is 27 cubic feet and covers 324 square feet at 1 inch deep or 81 square feet at 4 inches. Wetter, heavier soil covers less: at 1.3 tons per yard, a ton covers about 62 square feet at 4 inches.
How many bags of topsoil is 1 yard?
A cubic yard is 27 cubic feet: 27 bags of 1 cubic foot, 36 bags of 0.75 cubic feet, 18 bags of 1.5 cubic feet or 13.5 bags of 2 cubic feet.
How much soil do I need for a 4x8 raised bed?
A 4 × 8 ft bed filled 12 inches deep holds 32 cubic feet, or 1.19 cubic yards. That is 43 bags of 0.75 cu ft, 22 bags of 1.5 cu ft or 16 bags of 2 cu ft. Two beds need 64 cubic feet (2.37 yards).
How deep should topsoil be for a new lawn?
Penn State Extension says a minimum of 4 to 6 inches of good topsoil, measured after it settles, is typically needed for a new lawn. For a 1,000 square foot lawn, 4 inches is 12.3 cubic yards and 6 inches is 18.5 cubic yards.
Related calculators
Sources
- Penn State Extension, Lawn Establishment. A minimum of 4 to 6 inches (firmed or settled depth) of good topsoil; ideally 2 inches incorporated into the upper 2 to 3 inches of subsoil. Last checked 6 November 2026
- University of Maryland Extension, Growing Vegetables in Raised Beds. Beds on hard surfaces: at least 8 in for leafy greens, beans and cucumbers; 12 to 24 in for peppers, tomatoes and squash; at least 8 in of mix over poor existing soil. Last checked 6 November 2026
- University of Maryland Extension, Soil to Fill Raised Beds. Compost and purchased topsoil in a 1:2 or 1:1 ratio. Last checked 6 November 2026
- Scotts Miracle-Gro, Scotts Premium Topsoil product page. 0.75 cu ft bag; covers 4 sq ft in a 2 inch layer. Last checked 6 November 2026
See the methodology page for how YardageHQ builds and checks its calculators.