landscaping · 7 min read

How Much Topsoil Do I Need?

New lawns want 4–6 inches. Vegetable beds want 12 inches. Here's how to translate those depths into an accurate topsoil order.

Topsoil is the workhorse of a healthy landscape. Under a lawn it feeds the roots. In a garden bed it holds moisture and nutrients. As a grading material it corrects drainage and low spots.

The right amount depends on what you're building. This guide covers every common use — lawns, gardens, raised beds, grading — with the depths professionals actually specify.

How much topsoil by use case

ApplicationRecommended depth
New lawn (over prepared subgrade)4–6 inches
Lawn top-dressing / overseed0.25–0.5 inches
Sod installation3–4 inches
Annual flower beds8–12 inches
Perennial beds12 inches
Vegetable garden12–18 inches
Raised bedsFull container depth (usually 10–18 inches)
Grading / low spot fillAs needed (measure to grade)
Pro tip
Topsoil is not compost. For vegetable beds, mix topsoil 50/50 with compost and a small amount of coarse sand or perlite for drainage.

The volume formula

Once you know depth, the math is the same as any bulk material.

  • Cubic feet = length (ft) × width (ft) × depth (ft).
  • Depth in feet = depth in inches ÷ 12.
  • Cubic yards = cubic feet ÷ 27.

Worked example: 1,200 sq ft new lawn

At 5 inches deep: 1,200 × (5 ÷ 12) = 500 cu ft. That's 500 ÷ 27 ≈ 18.5 cubic yards. Add 15% for settling and you're ordering about 21.3 cubic yards.

Settling and compaction

Fresh topsoil settles 10–15% after watering and initial rains. Order slightly more than the calculated volume to avoid low spots that trap water later.

Warning
Never install topsoil over compacted clay without decompacting first. Water perches on the interface and drowns roots. Rototill the subgrade to at least 4 inches before spreading topsoil.

Screened vs unscreened

  • Screened topsoil is passed through a 0.5-inch or 1-inch screen. Cleaner, more expensive, and preferred for lawns and beds.
  • Unscreened topsoil is cheaper but contains rocks, roots, and lumps. Fine for grading and fill under gravel.
  • For premium lawns, ask for 'triple-mix' — a screened topsoil, compost, and peat blend.

Ordering by yard vs by ton

Most landscape yards sell topsoil by the cubic yard. Some sell by the ton. Dry screened topsoil averages 1.1 tons per cubic yard, but moisture content changes this significantly — wet topsoil can push 1.5 tons per yard.

Note
Always ask your supplier which unit their delivery truck is measured in. Volume is more predictable than weight for planning coverage.

Common mistakes

  • Under-ordering because you forgot the waste and settling factor.
  • Skipping soil testing on new lawns — pH and organic matter matter more than depth.
  • Installing topsoil over turf without stripping it first (buried grass rots and creates air pockets).
  • Mixing topsoil with construction fill and calling it 'graded soil'.

Frequently asked questions

How much does a cubic yard of topsoil cover?
At 4 inches deep, one cubic yard covers about 81 square feet. At 6 inches deep it covers 54 sq ft.
How much does a yard of topsoil weigh?
Dry screened topsoil: about 2,200 lb (1.1 tons). Wet topsoil: 2,600–3,000 lb (up to 1.5 tons).
Can I put topsoil over grass?
Only a very thin layer (under 0.5 inches) as a top-dress. Anything more buries and rots the grass. Strip existing turf before adding depth.
What's the difference between topsoil and garden soil?
Topsoil is a base — sifted dirt. Garden soil is topsoil pre-blended with compost, peat, and nutrients ready for planting.

Summary

Topsoil depth depends entirely on use — 4–6 inches for lawns, 12+ for beds. Convert to cubic yards, add 10–15% for settling, and decompact the subgrade before you spread.

Stay in the loop

Get new calculators and estimating updates.

Stay updated as Yardexa launches new calculators and estimating tools. One short email per month.

These results are estimates only. Confirm quantities, compaction, waste, and delivery requirements with your supplier or project professional before ordering materials.

Help Improve Yardexa

Help Improve Yardexa

We're constantly improving Yardexa based on feedback from homeowners, landscapers, contractors, and suppliers.