How Much Topsoil to Top Dress a Lawn: The Arithmetic

1.5 cubic yards per 1,000 sq ft at a quarter inch. The full table by area and depth, what a yard weighs, and how many bags that really is.

By Zakaria November 1, 2026 3 min read Save to Pinterest

A soil-caked garden spade standing in freshly dug ground — Photo: manfredrichter, Pixabay Content License, via Pixabay

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The formula is area × depth in inches ÷ 324 = cubic yards. Everything below is that, worked out so you do not have to.

The short answer

Area in square feet times depth in inches divided by 324 gives cubic yards: about 1.5 cubic yards per 1,000 square feet at a quarter inch, or 3 cubic yards at half an inch. Add ten percent. A cubic yard is roughly 27 one-cubic-foot bags, so bagged material stops being economic above about a quarter yard — a 1,000 square foot lawn needs around 40 bags. A yard of topsoil weighs 1,800 to 2,400 pounds dry and up to 3,000 wet, which is five or six wheelbarrow loads and more than a half-ton pickup should carry. Compost is lighter at 1,000 to 1,400 pounds a yard.

Formula: sq ft × depth in inches ÷ 324 = cubic yards
1,000 sq ft at 1/4 in = ~1.5 cu yd; at 1/2 in = ~3 cu yd
Add 10% for spillage and deeper hollows
27 bags to a cubic yard — bulk delivery above a quarter yard
~1 ton per cubic yard, heavier wet

The table

lawn area	1/4 in	1/2 in	3/4 in
250 sq ft	0.2 cu yd	0.4 cu yd	0.6 cu yd
500 sq ft	0.4 cu yd	0.8 cu yd	1.2 cu yd
1,000 sq ft	1.5 cu yd	3.0 cu yd	4.5 cu yd
2,000 sq ft	3.1 cu yd	6.2 cu yd	9.3 cu yd
5,000 sq ft	7.7 cu yd	15.4 cu yd	23.1 cu yd

Quarter inch is the standard pass. Half an inch is the maximum on all but the longest grass.

Bags against bulk

quantity	bagged (1 cu ft)	sensible?
0.25 cu yd	7 bags	Yes
0.5 cu yd	14 bags	Borderline
1 cu yd	27 bags	No — order bulk
3 cu yd	81 bags	Absolutely not

Weight, not volume, decides how you move it

A cubic yard is around a ton dry and up to a ton and a half wet. That is five or six wheelbarrow loads, and more than a half-ton pickup should legally carry. Have bulk material tipped as close to the lawn as the driveway allows.

Measuring an odd-shaped lawn

Break it into rectangles and triangles, calculate each, add them
Rectangle: length × width
Triangle: base × height ÷ 2
Circle: radius × radius × 3.14
No tape? An adult stride is close to three feet — within about ten percent over lawn distances

Topsoil or compost

material	weight per cu yd	best for
Screened topsoil	1,800–2,400 lb	Filling visible hollows
Compost	1,000–1,400 lb	Soil building, thatch reduction
50/50 blend	~1,600 lb	Both — the usual top-dressing mix

Whatever you buy, it must be screened. Unscreened soil carries stones and lumps that will not work down between the blades and will damage a mower.

Common questions

How much topsoil do I need to top dress a lawn?

About 1.5 cubic yards per 1,000 square feet at a quarter inch deep, or 3 cubic yards at half an inch. The formula is area in square feet times depth in inches, divided by 324, which gives cubic yards. So a 40 by 50 foot lawn at a quarter inch is 2,000 times 0.25 divided by 324, which is about 1.5 cubic yards. Add ten percent for spillage and for the hollows being deeper than they look.

How many bags is a cubic yard?

Roughly 27 bags at 1 cubic foot each, or about 13 to 14 of the larger 2 cubic foot bags. That is why bagged material stops making sense above about a quarter of a cubic yard — top dressing a 1,000 square foot lawn needs 40 bags, which costs several times a bulk delivery and takes an afternoon just to open. Order bulk by the yard for anything beyond a small patch.

What does a cubic yard of topsoil weigh?

Between 1,800 and 2,400 pounds dry, and up to 3,000 wet — so roughly a ton per yard, and more after rain. That matters twice: a half-ton pickup legally carries about half a yard of wet soil, not the two yards it looks like it would hold, and a yard shifted by wheelbarrow is five or six full loads. Compost is lighter at around 1,000 to 1,400 pounds per yard.

Should I buy topsoil or compost for top dressing?

Compost, or a blend, for most lawns. Screened topsoil is right when you are filling visible hollows and want body; compost is better when the goal is soil improvement and thatch reduction, and it is lighter to spread. A 50/50 blend does both and is what most suppliers sell as a top-dressing mix. Whichever you choose, it must be screened — unscreened soil carries stones and lumps that will not work down between the blades.

How do I measure an irregular lawn?

Break it into rectangles and triangles, work each one out, and add them up — that is accurate enough and far quicker than any formula for an odd shape. For a rough circle, multiply the radius by itself and then by 3.14. Pace it out if you have no tape: a normal adult stride is close to three feet, which is accurate to within about ten percent over a lawn-sized distance.

What if I order too much?

Spread the surplus on beds as a mulch, use it to fill low spots along paths and fence lines, or bank it for next season under a sheet so it does not grow weeds. Over-ordering by ten percent is deliberate and sensible. Running short is the expensive error, because a second delivery costs almost as much in haulage as the first and the lawn sits half-dressed in the meantime.

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Two cupped hands holding fine dark compost above a lawn

Lawn & Soil · Nov 1, 2026