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Calcumetryx

Materials

Topsoil Calculator

How much topsoil a lawn, seedbed or turfing job needs at a given dressing depth.

Topsoil
Start from
Area shape

Beds, drives, pads, plots

Depth of the topsoil dressing over the existing surface. Seeding and turfing want a shallow, even layer.

Volume needed

Volume needed: 2.96 cubic yards

cubic yards

Rectangular prism
depth exaggerated for legibility
20 ft12 ft4 in
Cubic feet
80cu ft
Cubic metres
2.27
Area covered
240ft²
Weight
tonsAdd a density to get tons. Your supplier has the figure for the exact product.

The working

  1. Area = Length × Width

    = 20 ft × 12 ft

    = 240 ft²

  2. Volume = Area × Depth

    = 240 ft² × 0.333 ft

    = 80 cu ft

  3. Cubic yards = Cubic feet ÷ 27

    = 80 ÷ 27

    = 2.96 cu yd

    1 cubic yard = 3 ft × 3 ft × 3 ft = 27 cubic feet

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

Specification
Formula version
1.0.0
Last reviewed
2026-09-01
External data
None

This tool uses only your inputs and exact unit conversions. No benchmark, average or market figure is built into it. How we calculate

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.

Worked example

A 50 ft × 30 ft lawn dressed 4 in deep

Given
Length
50 ft
Width
30 ft
Depth
4 in
Step by step
  1. Depth in feet= 4 in ÷ 12= 0.333 ft
  2. Area= 50 ft × 30 ft= 1,500 sq ft
  3. Volume= 1,500 sq ft × 0.333 ft= 500 cu ft
  4. Cubic yards= 500 ÷ 27= 18.5 cu yd
Order18.5 cubic yards
What it assumes
  • An even dressing depth across the whole area.
  • The volume is the loose spread volume before it is rolled or settles.
  • Unit conversions are exact.
  • Density 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.

Found a problem?