Topsoil Calculator
How much topsoil a lawn, seedbed or turfing job needs at a given dressing depth. How it works
Volume needed
cubic yards
- Cubic feet
- 80cu ft
- Cubic metres
- 2.27m³
- Area covered
- 240ft²
- Bags
- bags
- Weight
- tons
Show the calculationHide the calculation3 steps
The working
Area = Length × Width
= 20 ft × 12 ft
= 240 ft²
Volume = Area × Depth
= 240 ft² × 0.333 ft
= 80 cu ft
Cubic yards = Cubic feet ÷ 27
= 80 ÷ 27
= 2.96 cu yd
Topsoil is normally spread as a shallow, even dressing over what is already there. Enter the area and the depth you want on top; the volume is immediate, and tons appear if you supply a density.
How this calculator works
Only your inputs and exact unit conversions. Where a figure comes from anywhere else, it is recorded below with its source.
- Formula version
- 1.0.0
- Last reviewed
- 2026-09-01
- External data
- None
- Category
- Materials
What this calculates
The volume of topsoil needed to dress an area to a chosen depth, in cubic yards and its equivalents.
Dressing versus filling
Topsoil is a surface layer, typically a few inches, spread over an existing subgrade before seeding or turfing. It is not the same job as filling a bed to root depth or raising a level.
If your depth starts climbing past a foot, you are filling rather than dressing, and the fill dirt calculator accounts for the settlement that follows.
Why tons need a density from you
Screened topsoil varies with organic content and moisture. The density field stays empty and takes the figure for what is actually being delivered.
A 50 ft × 30 ft lawn dressed 4 in deep
- Length
- 50 ft
- Width
- 30 ft
- Depth
- 4 in
- 01Depth in feet= 4 in ÷ 12= 0.333 ft
- 02Area= 50 ft × 30 ft= 1,500 sq ft
- 03Volume= 1,500 sq ft × 0.333 ft= 500 cu ft
- 04Cubic yards= 500 ÷ 27= 18.5 cu yd
18.5 cubic yards
What it assumes
- 01An even dressing depth across the whole area.
- 02The volume is the loose spread volume before it is rolled or settles.
- 03Unit conversions are exact.
- 04Density and price are used only if you enter them.
What it does not do
- It does not allow for settlement or rolling, which reduce the finished depth slightly.
- It does not assume a density, so it cannot give tons on its own.
- It assumes the subgrade is already at the level you want under the dressing.
Common questions.
- How much topsoil do I need for a lawn?
- Multiply the area by the dressing depth and divide the cubic feet by 27. Enter the lawn above and the calculator shows every step.
- Is "top soil" different from "topsoil"?
- No — they are the same material and the same question, which is why there is one calculator rather than two near-identical pages.
- What is the difference between this and the soil calculator?
- This spreads a shallow dressing over an existing surface. The soil calculator fills a bed or planter to root depth, which is a deeper, different job.
Where people go next
Ordered by what usually comes next in the same job, not by keyword.