How much topsoil do I need to topdress a 500 sq ft lawn?

At a half-inch topdressing, the right depth for levelling and overseeding, 500 sq ft needs 500 × (0.5 ÷ 12) = 20.8 cubic feet, which is 0.77 cubic yards or 28 standard 0.75 cu ft bags. At a full inch it doubles to 41.7 cubic feet and about 1.54 cubic yards. Either way that is bulk territory. Never topdress deeper than an inch in a single pass — the grass has to grow up through whatever you spread, and a thick layer smothers it.

How deep should topsoil be for a new lawn?

Four to six inches is the standard, and it lines up with the depth extension services recommend rototilling to when preparing a seedbed — Michigan State and Missouri extension both work the top four to six inches. That band is where grass roots actually live, and thin soil sitting on compacted subgrade is the single most common reason a new lawn struggles. If the budget will not stretch that far, till two or three inches into the existing grade rather than laying a thin loose layer on top: blending beats layering for both root penetration and drainage.

How much does a cubic yard of topsoil weigh?

Roughly a ton and a bit when dry, and meaningfully more when wet. Penn State Extension uses 1.33 g per cubic centimetre for a silt loam, which is 82.99 lb per cubic foot, or about 2,240 lb per cubic yard. Soils generally fall between 1.0 and 2.0 g per cubic centimetre, so a sandy load runs heavier and a compost-rich blend lighter. Rain adds weight on top of that, which is why suppliers sell soil by volume and cap deliveries by truck payload rather than by the yard.

Can I plant directly into fresh topsoil?

For grass, yes — seed or sod straight into graded, lightly firmed topsoil. For vegetable beds and ornamental plantings, improve it first: bulk topsoil is variable and often low in organic matter, and benefits from two or three inches of compost worked into the top layer. Check that the load is screened, with no rock or root chunks, and let a soaking rain settle a deep fill for a week before planting. Fresh-dumped soil can sink an inch or two and take new plants down with it.

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Topsoil Calculator

Q: What is the difference between topsoil, garden soil, and fill dirt?

Topsoil is screened natural earth with organic matter in it, the general-purpose growing layer for lawns and beds. Garden soil is topsoil already blended with compost and amendments, sold in bags at a premium; it is right for raised beds and vegetable plots and wasteful to spread by the cubic yard. Fill dirt is subsoil with little organic content: cheap, structurally stable, used for filling holes and rough grading, and plants hate it. For a deep low spot, fill with fill dirt and cap the top four to six inches with real topsoil.

Cubic yards and bags for beds, lawns, and topdressing — with the right depth for each job.

Updated August 5, 2026

Area length10 ft

Area width10 ft

Topsoil depth4 in

You need

1.23cubic yards

what to ask for when ordering bulk delivery

Volume: 33.3 cu ft
Bags equivalent: 45 bags

In short

How much topsoil do I need?

One cubic yard of topsoil covers 324 square feet at 1 inch deep, 108 square feet at 3 inches, and 81 square feet at 4 inches. Multiply length by width by the depth in inches, divide by 12 for cubic feet and by 27 for cubic yards. A 10 by 10 ft area at 4 inches is 33.3 cubic feet, or 1.23 cubic yards.

A cubic yard of dry mineral soil weighs well over a ton, so the bag count climbs faster than your back will like.

How to use the topsoil calculator

Measure the area in feet, length times width, and split irregular spaces into rough rectangles you add together. For a curved bed use the average of the widest and narrowest measurements.

Lawn areas are usually the big number here, so pace them off properly or pull the dimensions from a property plat rather than eyeballing from a window: being twenty percent out on a bed costs you a bag, while being twenty percent out on a lawn-sized area costs you an afternoon and a second delivery.

Where you are filling an existing depression rather than laying an even layer, probe the depth in several spots and enter the average, not the deepest point.

1.23 yd³

The default area

10 by 10 ft at 4 inches

45 bags

Same volume in 0.75 cu ft bags

≈2,240 lb

One dry cubic yard

Penn State silt loam figure

Depth is where topsoil parts company with mulch math. A new planting bed or a lawn started from bare grade wants four to six inches of quality soil, which is the rootzone depth Michigan State and Missouri extension services both use for seedbed preparation and the depth they recommend rototilling to.

Topdressing an existing lawn to smooth low spots or feed thin turf is the opposite extreme: half an inch to one inch, and no more, because grass has to grow up through whatever you spread. Raised-bed fills and badly eroded areas can run the slider to eight inches — calculate those per layer if you are alternating soil and compost rather than pouring one homogeneous depth.

Seeding the new lawn next?

Seed is quoted as a rate per thousand square feet rather than a volume, so once the rootzone is graded and firmed it is a separate number with its own page.

Open the grass seed calculator →

The result reads two ways. Cubic yards is the bulk-delivery number a dump-truck quote uses, and the bag count converts the same volume into store bags, defaulting to the common 0.75 cubic foot bag with 1 and 1.5 cubic foot options under Advanced. Topsoil bags are small and heavy, so the count climbs alarmingly: a cubic yard is 36 of the standard bags, and even a modest bed becomes dozens.

That is why bulk wins earlier with soil than with almost any other landscape material — past roughly half a cubic yard, a delivery or a pickup load from the yard beats carrying sacks. Reserve bags for patches, containers, and spots a truck cannot reach. This is a shopping estimate, not a landscaper’s takeoff.

Pace a lawn off properly or pull the dimensions from a property plat.
Probe a depression in several spots and enter the average depth.
Give a new lawn or planting bed four to six inches of rootzone.
Check your vehicle payload rating before fetching a cubic yard yourself.

Don't

Topdress existing turf deeper than an inch in a single pass.
Spread fill dirt anywhere you intend to grow something.
Pay growing-medium rates to backfill the bottom of a deep low spot.
Carry sacks past roughly half a cubic yard when a delivery beats them.

What one cubic yard of topsoil covers at each depth, alongside what 100 square feet costs you in yards, in standard bags, and in weight you have to move. The weight column is the one that decides whether you order bulk or carry sacks.

Depth	Sq ft covered by 1 cubic yard	Cubic yards per 100 sq ft	0.75 cu ft bags per 100 sq ft	Approx dry weight per 100 sq ft
0.5 in — light topdressing	648	0.15	6	350 lb
1 in — maximum topdressing pass	324	0.31	12	690 lb
1.5 in — levelling a low spot	216	0.46	17	1,040 lb
2 in — blending into grade	162	0.62	23	1,380 lb
2.5 in — thin bed build-up	129.6	0.77	28	1,730 lb
3 in — shallow planting bed	108	0.93	34	2,080 lb
3.5 in — near rootzone depth	92.6	1.08	39	2,420 lb
4 in — minimum lawn rootzone	81	1.23	45	2,770 lb
5 in — comfortable new lawn	64.8	1.54	56	3,460 lb
6 in — full rootzone	54	1.85	67	4,150 lb
7 in — raised bed or deep repair	46.3	2.16	78	4,840 lb
8 in — this tool’s maximum	40.5	2.47	89	5,530 lb

Computed July 2026 from the same engine this page runs, at 27 cubic feet per cubic yard and the 0.75 cu ft standard bag. Weight uses 83 lb per cubic foot, the figure Penn State Extension applies to a silt loam at 1.33 g/cm3; sandy soils run heavier and wet soil heavier still.

Topsoil, garden soil, or fill dirt?

Know what you are actually buying, because the words mean different things at the supply yard. Topsoil is screened earth with some organic content: the general-purpose growing layer. Fill dirt is subsoil — cheap, structureless, stable under a slab, and wrong for anything you intend to grow.

Garden soil is topsoil pre-blended with compost and sold at a premium, sensible for raised beds and vegetable plots and wasteful to spread by the yard. This calculator’s volume works for any of them; the label on the pile decides what belongs in it. For a deep low spot, fill with fill dirt and cap the top four to six inches with real topsoil rather than paying growing-medium rates for backfill.

Area x depth -> cubic yards, the same math the calculator runs.

Full guide

How Much Topsoil Do I Need? Lawns, Beds & Topdressing

The volume formula, the right depth for each job, and how topsoil differs from garden soil, compost, and fill dirt.

Read the full guide →

The formula, worked line by line

Topsoil is straight volume: the area you are covering multiplied by how deep you want it. What makes it error-prone is that the numbers arrive in three units. You measure the bed or lawn in feet, you choose the depth in inches, and bulk soil is sold by the cubic yard, so two conversions sit between the measurement and the order.

Dividing the depth by 12 converts inches to feet so the product is genuinely cubic feet. Dividing by 27 converts cubic feet to cubic yards, because a cubic yard is three feet on every side. Almost every catastrophically wrong soil order traces back to one of those two divisions being skipped — and unlike a paint estimate, a soil estimate that is out by a factor of twenty-seven arrives on a truck.

cubic feet = length ft × width ft × (depth in ÷ 12)
cubic yards = cubic feet ÷ 27
bags = cubic feet ÷ bag size, rounded UP to a whole bag
sq ft covered by one cubic yard = 324 ÷ depth in inches

Same volume math as mulch: area times depth, converted to yards and bags.

The default area, in yards and bags

Volume: 10 × 10 × (4 ÷ 12) = 33.33 cu ft
Cubic yards: 33.33 ÷ 27 = 1.23
Standard 0.75 cu ft bags: 33.33 ÷ 0.75 = 44.4
Bags to buy: 45

One volume, two completely different shopping trips: a quarter of a truckload, or forty-five sacks to lift twice each. The bag count is the argument for bulk, not a suggestion.

Useful anchors to carry around. A cubic yard covers 324 square feet at one inch, 108 at three, and 81 at four — the same figures UGA Extension prints in its horticultural conversion tables. Maryland Extension puts one inch of material over 1,000 square feet at about three cubic yards, which is the identical arithmetic from the other direction. And a cubic yard is 36 standard bags, 27 of the one-cubic-foot bags, or 18 jumbo 1.5 cu ft bags.

Questions people ask

Sources

Where the constants and formulas on this page come from. Each line names the figure it backs.

The published coverage figures this page matches: a cubic yard covering 324 square feet at one inch, 108 at three and 81 at four.
Conversion Tables, Formulas and Suggested Guidelines for Horticultural Use, Bulletin 931 — University of Georgia Cooperative Extension

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