Pick the job rather than a depth, and the depth comes with it — from Penn State for a new lawn, from Clemson for topdressing and for improving a bed. You get cubic yards, bags, and a tonnage range, because a yard of soil weighs two thirds more wet than loose.
1,500 sq ft at 0.5″ for topdressing a lawn
2.3 cubic yardsThat is 63 cu ft, or 63 bags of 1 cu ft. One cubic yard covers 648 sq ft at this depth.
- Area
- 1,500 sq ft
- Depth
- 0.5″
- Volume
- 2.31 cu yd (63 cu ft)
- Bags of 1 cu ft
- 63
- Weight
- 2.4–3.9 tons
Over living grass, half an inch at a time is a ceiling and not a target — a thick layer smothers the lawn you were improving. And for a new lawn, remember the depth Penn State gives is the settled one: spread deeper, firm it, then measure.
Depths and sources checked 2026-09-24.
Quick answer: a cubic yard of topsoil covers 324 sq ft at 1 inch, so a 1,500 sq ft lawn topdressed at the maximum ½ inch takes about 2.3 cubic yards. Clemson’s ceiling for topdressing is “no more than ½-inch of material applied at a time”; Penn State’s figure for a new lawn is “a minimum of 4 to 6 inches (firmed or settled depth) of a good-quality topsoil”. A yard of topsoil weighs 2,050 lb loose, 2,565 lb packed and 3,375 lb wet — which is why the tonnage here is a range and not a number.
How to use it
Pick the job first. The depth follows from it, because the depth is not a matter of preference: topdressing over living grass has a ceiling, a new lawn has a minimum, and improving a bed is a different figure again. Then measure the area and read off the cubic yards a supplier will quote in, the bags if you are carrying it, and the weight range if the quote is by the ton.
The depth each job needs
| Job | Depth | Whose figure |
|---|---|---|
| Topdressing a lawn | no more than 0.5 inches | Clemson Cooperative Extension |
| Filling low spots in a lawn | no more than 0.5 inches | Clemson Cooperative Extension |
| A new lawn | 4–6 inches | Penn State Extension |
| Improving an existing bed | no more than 3 inches | Clemson Cooperative Extension |
The two ceilings are the interesting ones. Over grass that is alive, more is not better at any point: a thin layer works down between the blades and improves the soil beneath, a thick one shades the plant out. And when Penn State says 4 to 6 inches for a new lawn, the words in brackets — “firmed or settled depth” — are the ones that cost people a second delivery.
Levelling a bumpy lawn takes more than one weekend
This is the job the calculator is most often used for, and the answer is usually “in stages”. A hollow two inches deep cannot be filled in one go, because half an inch is the most the grass will grow through. Work out the volume for the deepest part, then apply it in half-inch passes across a season, letting the grass come through each one before the next. If the dip is deeper than an inch or two, it is quicker to cut the turf, lift it, fill underneath and lay it back than to bury it four times.
The other half of levelling is finding out why it sank. A soft line across a lawn is often a trench that was backfilled loose; a saucer under a tree is usually roots. Filling the symptom works on the first; it does not on the second.
Topsoil, garden soil, compost — not the same bag
Bagged “topsoil” is mineral soil, usually screened, and is what you want for levelling and for building a lawn. “Garden soil” and “raised bed mix” are blends with compost in them, sold for beds, and they settle far more. Compost on its own is an amendment, not a soil: it is what Clemson recommends topdressing with to improve structure, and a lawn built on pure compost slumps. Match the material to what is already there — a sand layer over clay creates a boundary water will not cross, which is a drainage problem rather than a fix.
Why the weight is a range
The published chart gives topsoil three weights for the same cubic yard: 2,050 lb loose, 2,565 lb packed and 3,375 lb wet. So the same order can weigh two thirds more after a wet week, and a price per ton means different amounts of soil on different days. Buy by the yard where you can, and where you cannot, ask which condition the ton price assumes.
Order for the settled depth
Nothing here adds a settling factor, because none is published — but the effect is real, and Penn State’s wording admits it by specifying the settled depth rather than the loose one. In practice, for a new lawn, spread deeper than the figure you want and firm it down before you seed. For topdressing there is nothing to allow for: half an inch is half an inch, and it disappears into the sward within a couple of mows.