Topsoil Calculator
A free topsoil calculator. Enter your length, width, and depth to find cubic yards of topsoil needed, how many bags that equals for common bag sizes, and an estimated total cost.
This free topsoil calculator converts your length, width, and depth into cubic yards, counts the bags you need for common 0.75, 1, 1.5, or 2 cubic foot bag sizes, and estimates your total cost from a price per cubic yard.
Your topsoil estimate
Soil settles and spills. Order 5 to 10 percent more than the math shows. See Terms of Use.
How deep should topsoil go
The depth you need depends on what you are growing. A lawn being topdressed to smooth bumps and feed roots only needs about 1/4 inch of screened topsoil worked into the turf. That thin layer avoids smothering the grass while still delivering organic matter. Ordering a full truckload for topdressing is usually overkill, and bags are easier to manage for thin coats.
A brand new lawn seeded from scratch wants 4 to 6 inches of quality topsoil under the seed or sod. Grass roots grow deepest when they have room to chase moisture downward, and shallow soil dries out fast in summer. Measure your existing soil depth before ordering, since many yards already have a few inches of decent soil after you strip away weeds and debris.
Raised and in-ground garden beds call for 8 to 12 inches of topsoil, and vegetables are the reason. Most vegetable roots feed in the top 8 inches, and dense native clay blocks drainage below that. Amending or replacing that layer with loose, compost-rich topsoil gives roots the air and water they need. For beds deeper than 12 inches, fill the bottom with fill dirt and reserve topsoil for the top layer to save money.
For grading, filling low spots, or building up a slope, depth varies with the project, often 2 to 6 inches before compaction. Soil settles, so order 5 to 10 percent more than the calculator shows and rake it a little proud of the final grade. Water or roll the area, then check for dips before you seed or plant.
Topsoil calculator questions
How do I calculate topsoil in cubic yards?
Multiply length times width times depth in feet to get cubic feet, then divide by 27. For a 20 by 10 foot bed at 4 inches deep: 20 times 10 times 0.33 is 66.7 cubic feet, divided by 27 is about 2.5 cubic yards.
How many bags of topsoil do I need?
Divide your total cubic feet by the bag size. This calculator offers 0.75, 1, 1.5, and 2 cubic foot bags and rounds up to whole bags. For 66.7 cubic feet with 2 cu ft bags, you need 34 bags. Ordering by the cubic yard is usually cheaper for larger jobs.
How much does a yard of topsoil weigh?
Roughly 2,000 pounds, about one ton, for dry screened topsoil. Wet soil weighs more, which is why bagged soil lists cubic feet instead of pounds.
What is the difference between topsoil and fill dirt?
Topsoil is the dark, organic-rich upper layer that plants grow in. Fill dirt is the subsoil below it: cheaper, denser, and mostly mineral. Fill dirt is good for raising grades and filling holes, but poor for planting.
How much topsoil should I add to a low lawn?
For minor unevenness, topdress with about 1/4 inch and let the grass grow through it. For low spots deeper than 2 inches, fill in layers and settle each layer before adding the next.