Works for a lawn top-dress, a garden bed or a stack of raised beds — yards, bags, weight and cost, with the settling allowance soil actually needs.
½–1 in to top-dress a lawn · 4–6 in for a new lawn over subsoil · 10–12 in to fill a raised bed · 18–24 in for deep-rooted vegetables.
Weights are for moist soil. Topsoil is heavy — a single cubic yard is roughly a ton, which is more than most half-ton pickups should legally carry.
%
Loose soil settles and compost breaks down. 10% for a lawn, 15–20% for raised beds, which visibly drop in the first season.
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The calculation
Area × depth = volume, with depth converted from inches to feet by dividing by 12, then divided by 27 to reach cubic yards. A 4 × 8 ft raised bed filled 12 inches deep is 32 ft² × 1 ft = 32 ft³, or 1.19 cubic yards before any allowance for settling.
Why topsoil needs a bigger allowance than gravel
Aggregate settles because it compacts. Soil settles because it compacts and because the organic fraction decomposes. A raised bed filled level in April is routinely two inches down by September, which is why 15–20% is a sensible allowance rather than the 5–10% you would add to a stone order.
Weight is the constraint people forget
Material
lb per ft³
Weight per cubic yard
Screened topsoil
80
~2,160 lb
Unscreened topsoil
90
~2,430 lb
Garden soil blend
65
~1,755 lb
Compost
45
~1,215 lb
Peat moss
25
~675 lb
A cubic yard of damp topsoil weighs more than a ton. A half-ton pickup is rated for around 1,000 lb of payload, so a single yard already exceeds it — which is why yards deliver soil rather than let you collect it.
The answer depends entirely on the job, and the four common jobs want very different depths. Top-dressing an existing lawn takes half an inch, sometimes an inch — a surprisingly small volume that people routinely over-order tenfold. Establishing a new lawn over subsoil wants four to six inches of decent soil for roots to work in. Filling a raised bed takes ten to twelve inches. Growing carrots, parsnips or potatoes properly wants eighteen or more.
Filling raised beds cheaply
Filling a deep bed entirely with bought topsoil is expensive and unnecessary. The lower third can be coarse organic material — branches, turf sods laid upside down, leaves — which breaks down over a couple of seasons and improves drainage. Calculate the full depth here, then order for the top two thirds and expect to top up next spring as the base collapses.
Screened or unscreened
Screened topsoil has been passed through a mesh to remove stones, roots and debris. It costs more, spreads more evenly and is worth it for beds and lawns. Unscreened is fine for bulk filling, regrading or building up levels where nothing will be planted immediately.
Order a little over, not a little under
Bulk soil is sold in half-yard increments and the marginal cost of the extra half yard is small next to a second delivery fee. Leftover topsoil always finds a use; a bed left two inches short in October does not fill itself.
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Frequently asked questions
How many cubic yards of topsoil do I need?
Multiply the area in square feet by the depth in inches, divide by 12 to get cubic feet, then divide by 27. A 4 × 8 ft raised bed at 12 inches deep needs about 1.2 cubic yards before adding a settling allowance.
How much does a cubic yard of topsoil weigh?
Roughly 2,000 to 2,400 pounds when moist — about a ton. Screened topsoil is around 2,160 lb per yard. Wet clay-heavy soil can exceed 2,700 lb, which is beyond what most half-ton pickups should carry.
How many bags of topsoil make a cubic yard?
Twenty-seven 1 cubic foot bags, or about 36 of the 0.75 ft³ bags sold in many garden centres. Bagged soil typically costs two to three times as much per yard as bulk delivery.
How deep should topsoil be for a new lawn?
Four to six inches of quality topsoil over prepared subsoil. Less than four inches leaves grass roots shallow and drought-prone; more than six is rarely worth the cost for turf alone.
How much soil do I need for a 4x8 raised bed?
About 32 cubic feet, or 1.2 cubic yards, to fill it 12 inches deep. Add 15% for settling and you are ordering roughly 1.5 cubic yards, or around 40 one-cubic-foot bags.