Topsoil Calculator
Find out how many cubic yards — or bags — of topsoil you need for a lawn, garden bed, or leveling job.
Area dimensions
Results
For a 20 ft × 10 ft area at 4 in deep, you'll need about 2.47 cubic yards of topsoil — that's 45 bags at 1.5 cu ft per bag.
Topsoil needed
2.47 cubic yards
That's a mid-size amount — typical for building several garden beds or repairing a section of lawn.
This is where bulk delivery usually starts beating bags on price. Ask the supplier whether the soil is screened (rocks and roots removed) and what it's blended with — 'topsoil' has no enforced standard, so quality varies widely between yards.
Bagged equivalent: 45 × 1.5 cu ft bags
Area covered: 200 sq ft
Fresh topsoil settles roughly 10–20% after spreading and watering — if your finished grade matters (a lawn or a bed you'll plant immediately), buy toward the high side or plan a light second pass.
How this works
The calculator multiplies your area's length by its width, then by the topsoil depth you choose, to get an in-place volume — reported in cubic yards (the unit bulk soil is sold by) and as a whole-bag count for the retail bag size you select from the common 0.75, 1, 1.5, and 2 cubic foot options. Bags are always rounded up to the next whole bag, since partial bags can't be bought. The default 4 inch depth follows extension-service guidance recommending roughly 4–6 inches of quality topsoil for lawn establishment and bed building; shallower jobs — topdressing at a half inch, leveling at 1–2 inches — use the same math at your entered depth. One behavior is disclosed rather than hidden in the number: fresh topsoil settles roughly 10–20% after spreading and watering, and this calculator reports geometric volume without silently inflating it, so you can decide whether your job's finished grade justifies ordering the buffer. The model assumes a rectangular area at uniform depth — for L-shapes, run it per rectangle and add; for genuinely varying fill depths (regrading a slope), split the area into zones of roughly constant depth. The unit toggle switches all inputs and results between imperial and metric; internally every calculation runs in canonical units, so toggling never introduces rounding drift Depth guidance (4–6 inches for lawns and beds): University of Minnesota Extension.
Worked example
A 20 ft × 10 ft area being built up into a new planting bed at the default 4 inch depth: the area is 200 sq ft, and 4 inches is 1/3 of a foot, so the volume is 200 × 1/3 ≈ 66.7 cubic feet — about 2.47 cubic yards. In bags, that's 66.7 ÷ 1.5 = 44.5, rounded up to 45 of the common 1.5 cu ft bags. At this size the bulk-versus-bagged decision is clear-cut: 45 bags is over a ton of lifting in 30–40 lb increments, and bulk suppliers deliver 2.5 yards as a routine small load.
A second example: topdressing a lawn
A 40 ft × 25 ft lawn (1,000 sq ft) being topdressed to smooth out minor unevenness at 1/2 inch — the maximum single-pass depth existing grass reliably grows through: 1,000 sq ft × (0.5/12) ft ≈ 41.7 cubic feet, about 1.54 cubic yards, or 28 bags at 1.5 cu ft. Notice the counterintuitive result: a whole lawn at a half inch needs less soil than the small 200 sq ft bed in the first example at 4 inches. Depth dominates topsoil quantity, which is why guessing it is the costliest estimating mistake on this page.
Common mistakes
Ordering by area and guessing the depth
Topsoil quantity is a volume, and depth is the term people guess worst: the difference between 'a couple inches' and 4 inches doubles the order. Measure the depth you actually need against the job — 4–6 inches for new lawns and beds per extension guidance, 1–2 inches for leveling, a half inch for topdressing — and let the calculator do the multiplication rather than estimating yards by eye.
Spreading a thick layer over compacted subsoil
Topsoil laid over hard-panned, compacted ground creates a perched layer: roots and water stop at the interface, the new soil dries out fast, and the lawn above it struggles in the first hot spell. Till or at least deeply scarify the existing surface first so the new soil keys into the old — the goal is a transition, not a laminate.
Buying unscreened 'topsoil' because it's cheapest
There is no legal standard for what can be sold as topsoil. The cheapest product at some yards is unscreened site strippings — rocks, roots, weed seed bank and all. Ask specifically whether the soil is screened, what mesh size, and where it was sourced; a supplier who can't answer is telling you something. The price gap between screened loam and mystery fill is small compared to the labor it saves.
Ignoring settling when the finished grade matters
Fresh soil settles 10–20% after spreading and watering. Fill a trench or a bed exactly to grade and it will be a visible depression by autumn. Where the final level matters — lawn meeting a walkway, a bed edged to a path — overfill slightly (crowned an inch or so), water it in, and top up once it settles rather than trying to nail the grade in one pass.
Smothering existing grass with too-deep topdressing
The most common lawn-repair failure: dumping an inch or more of soil across live turf to 'level it', which blocks light and kills the grass underneath, leaving bare soil that erodes into the low spots you were fixing. Topdress at 1/4–1/2 inch per pass, rake until grass blades show through, and repeat in a few weeks — slower, but the lawn survives the treatment.
Having the pile dumped in the wrong place
A few yards of topsoil is several tons that only moves by shovel and wheelbarrow once it's on the ground. Before the truck arrives, decide the spot: close to the work, on a tarp (soil stains concrete and kills grass under a pile within days), clear of overhead lines for a dump body, and never on a septic field or soft lawn a loaded truck would rut. Delivery drivers dump where they can, not where you wished.
Using topsoil where the job needs a different material
Topsoil is not a structural fill — under a shed slab, patio, or paver base it keeps settling and holding moisture for years; those jobs need compacted gravel. It's also the wrong product for container growing (too dense, poor drainage in pots — use potting mix) and a poor mulch substitute on top of beds. Matching material to function is most of the battle in landscape ordering.
When this calculator's model stops applying
- Sloped ground being regraded: cut-and-fill jobs need soil only where you're building up, and the depth varies continuously across the slope. Estimate by splitting the area into zones of roughly constant fill depth and running the calculator per zone — a single average depth over the whole area can be badly wrong on a real slope.
- Very deep fills (over about a foot): deep fills must be placed in watered, lightly compacted lifts, and settle far more than the surface-layer 10–20% figure. For filling a former pool, stump hole, or major grade change, expect to return with additional material over one or more seasons.
- Clay-heavy or waterlogged sites: adding topsoil on top of a drainage problem raises the problem, it doesn't fix it. If water stands on the area now, address drainage (grading, French drain, amendment of the subsoil) before ordering fill by this calculator.
- Turf laid the same day: sod suppliers commonly specify their own prepared-depth requirements (often 4–6 inches of amended, firmed soil, graded an inch below hard edges to account for sod thickness). Follow the sod supplier's spec where it differs from the general default here.
- Containers, planters, and green roofs: weight-limited applications use engineered lightweight growing media, not field topsoil — a saturated cubic yard of topsoil can exceed a ton, which is a structural load, not a gardening decision.
- Erosion-prone or bare slopes steeper than roughly 3:1: loose spread topsoil washes off a steep slope in the first storm. These need erosion-control measures (blankets, terracing, hydroseed over minimal dressing), and quantity is driven by the control method, not this area × depth model.
- Contaminated or urban infill sites: where soil quality of the existing ground is suspect (old industrial land, lead-paint-era house perimeters), the question is remediation and imported certified soil depth, which is a site-assessment output — not a homeowner volume estimate.
FAQ
How deep should topsoil be?
It depends on the job. Extension-service guidance recommends roughly 4–6 inches of quality topsoil for establishing a new lawn or building a planting bed — this calculator defaults to 4 inches for that reason. Lawn repair and topdressing use far less: 1/4 to 1/2 inch raked into existing grass per pass (more smothers the turf), and leveling low spots typically takes 1–2 inches worked in gradually. Vegetable beds benefit from the deeper end, 6 inches or more of amended soil.
How many bags of topsoil are in a cubic yard?
A cubic yard is 27 cubic feet, so it's 36 bags at 0.75 cu ft (the common Scotts bag size), 27 bags at 1 cu ft, 18 bags at 1.5 cu ft, or about 14 bags at 2 cu ft. That's why bulk delivery wins on price quickly: a yard's worth of small bags often costs two to three times the bulk per-yard rate, before you've carried three dozen 40 lb bags across the yard.
Should I buy bagged or bulk topsoil?
Under about a cubic yard, bags usually win on convenience — no delivery fee, no pile on the driveway, and you can spread over several weekends. Above a yard or two, bulk wins on price and handling. The quality calculus differs too: bagged topsoil is screened and consistent but sometimes heavy on cheap filler; bulk soil quality varies by supplier, so inspect a handful before ordering — it should be dark, crumbly, and free of rocks, roots, and a sour or chemical smell.
How much does a cubic yard of topsoil weigh?
Roughly 1 to 1.3 tons (2,000–2,700 lb) depending on moisture and organic content — dry screened loam at the light end, wet clay-heavy soil at the heavy end. That matters for two practical reasons: a standard pickup truck is realistically limited to about half a yard to a yard of soil, and a delivered pile should never be dumped on a surface that can't take the point load, like a septic field or a thin asphalt drive.
Why does the delivered pile look bigger than what I calculated?
Freshly excavated and screened soil is fluffed — full of air. After spreading, watering, and a few weeks of natural compaction it settles by roughly 10–20%. This calculator reports the in-place volume your project needs; if your finished grade matters (a lawn you're seeding immediately, or a bed that must meet a path edge), order 10–20% extra or plan a light topping-up pass after the first good rain.
What's the difference between topsoil, garden soil, and compost?
Topsoil is the base product: screened natural soil, sold for filling, grading, and building volume. Garden soil is topsoil blended with compost and sometimes fertilizer, formulated (and priced) for planting directly into. Compost is pure decomposed organic matter — a soil amendment, not a fill material; used alone it slumps dramatically as it continues to decompose. For big volume, the economical pattern is bulk topsoil for the body of the work, amended with compost in the root zone.
What does 'screened' topsoil mean and is it worth it?
Screened topsoil has been passed through a mesh (commonly 1/2 or 3/4 inch) to remove rocks, roots, and clods, leaving a uniform crumbly texture. Unscreened 'fill soil' is cheaper but can hide rubble, construction debris, and clay lumps. For anything you'll plant or seed into, screened is worth the difference — picking rocks out of a spread yard of unscreened soil costs far more time than the screening premium costs money.
Can I level my lawn with topsoil without killing the grass?
Yes, if you go thin: existing grass grows through up to about 1/2 inch of topdressing raked down until blades show. Anything deeper smothers it. Fill dips over 1/2 inch in multiple passes a few weeks apart, or for holes deeper than an inch or two, cut and lift the sod, fill underneath, and relay it. This is the classic use of the 0.5-inch depth end of this calculator's range.
How much topsoil do I need for a raised bed?
Use the bed's interior dimensions and its full depth in this calculator — an 8 ft × 4 ft bed filled 10 inches deep needs about 1 cubic yard. Two topsoil-specific notes: fill in watered lifts rather than all at once, because a deep loose fill settles several inches in the first season; and for growing beds most gardeners blend roughly one-third compost into the topsoil rather than filling with topsoil alone.
When is the best time to spread topsoil on a lawn?
During active growing season for your grass type — early fall or spring for cool-season lawns, late spring for warm-season — so the grass can grow up through the dressing and knit the new soil in. Avoid spreading onto dormant or stressed turf, and avoid working soil when it's saturated: spreading wet topsoil compacts it into exactly the airless layer you're trying to fix.
Does the calculator account for settling?
No — deliberately. It reports the geometric volume of your area at your chosen depth, and discloses the 10–20% settling behavior in prose instead of silently inflating the number, so you can decide based on whether your finished grade is critical. A bed you'll top up next season doesn't need the buffer; a lawn grade meeting a patio edge does.
Can I switch between imperial and metric partway through?
Yes — the unit toggle converts every field you've already entered, so you won't lose your measurements. Internally the tool always computes from the same canonical values regardless of which unit is displayed, so switching back and forth doesn't introduce any rounding error into the result.