How to use this calculator
- Choose the job. Leveling low spots, a topsoil layer for a new lawn, or filling an area. Each sets a starting depth you can change.
- Add the areas. For lawn dips, measure each low spot and estimate its average depth with a straightedge and ruler.
- Pick a bag size and, optionally, enter bag and bulk prices.
The formulas
- Cubic feet = area (sq ft) × depth (in) ÷ 12
- Cubic yards = cubic feet ÷ 27
- Leveling passes = depth ÷ ½ inch, rounded up
Worked example: leveling a dip
A low spot about 10 feet by 6 feet, averaging 1½ inches deep:
- Volume: 10 × 6 × 1.5 ÷ 12 = 7.5 cubic feet
- Passes: 1.5 ÷ 0.5 = 3 passes of about 2.5 cubic feet each
- In 0.75-cubic-foot bags: 10 bags in total, about 4 per pass
Leveling a lawn the right way
Clemson Cooperative Extension recommends “light and frequent” topdressing, with no more than ½ inch applied at a time; heavier layers can stunt the grass or shade it out. Rake the soil so it sifts down between the grass blades, and let the grass grow up through it before the next pass. Topdress while the lawn is actively growing.
- Match your soil. Use sand only if your native soil is sandy. On other soils, use a screened topsoil similar to what you have.
- Check what you buy. Topsoil and river sand can carry weed seeds, and nutrient levels vary, so buy from a reputable supplier and consider testing it.
- For deep dips, many people cut and lift the sod, fill underneath with soil, firm it, and lay the sod back down rather than making many thin passes.
Topsoil for a new lawn
A new lawn needs enough good soil for deep roots. The University of Nebraska–Lincoln recommends at least 4 inches of topsoil before laying sod, and Iowa State University suggests 4 to 6 inches of good topsoil when seeding. See our guides to laying sod and overseeding.
Sources
- Clemson Cooperative Extension: Topdressing a home lawn
- University of Nebraska–Lincoln: Establishing lawns from sod
- Iowa State University Extension: Late summer and fall lawn care
Frequently asked questions
How much topsoil do I need to level my lawn?
Measure each low area and its average depth, then multiply area by depth in inches and divide by 12 for cubic feet. A 10 by 6 foot dip that is 1½ inches deep needs 7.5 cubic feet, spread in three passes of no more than ½ inch each.
How thick can I topdress a lawn at one time?
Clemson Cooperative Extension recommends no more than ½ inch of material at a time. Thicker layers can smother and stunt the grass. Let the grass grow up through each layer before adding more.
Should I use sand or topsoil to level a lawn?
Match the material to your existing soil. Clemson Extension advises using sand only if your native soil is sandy; otherwise use a topsoil similar to what you have. Layers of very different materials can interfere with water movement.
How deep should topsoil be for a new lawn?
The University of Nebraska–Lincoln recommends at least 4 inches of topsoil under a new lawn from sod, and Iowa State suggests 4 to 6 inches of good topsoil when seeding.
How many bags of topsoil are in a cubic yard?
A cubic yard is 27 cubic feet: 36 bags of 0.75 cubic feet or 27 bags of 1 cubic foot. Above a cubic yard, bulk topsoil is usually far cheaper.