How Much Topsoil Do I Need? Formula, Depths & Worked Examples

Planning estimate, not a delivery quote. Every topsoil order is one formula plus one judgment call: the depth. This guide gives you both, with worked examples — then run your area through our topsoil calculator.

The formula

Cubic yards = length (ft) × width (ft) × depth (ft) ÷ 27, because one cubic yard is 27 cubic feet. Depth is almost always measured in inches, so convert first (inches ÷ 12 = feet) — or use the shortcut: square feet × depth in inches ÷ 324. One cubic yard covers 324 square feet at 1 inch deep, or 81 square feet at 4 inches deep.

Depth targets by project

Depth is where orders go wrong, so match it to the job: leveling and thin cover 2–3 inches; new lawn 4–6 inches firmed; vegetable and flower beds 6–12 inches; raised beds filled to the box depth, often 12+ inches; topdressing an existing lawn just 1/2 inch per pass (more smothers the grass). When in doubt, measure the depth you actually want in place — not the depth of the loose pile.

Bags vs bulk

One cubic yard equals 27 one-cubic-foot bags, 14 two-cubic-foot bags, or about 36 forty-pound (0.75 cu ft) bags. Bagged soil costs several times more per yard than bulk, but wins for small patches where a delivery fee would dominate. The break-even sits around 1 cubic yard: below it, bags; above it, bulk delivery, even with a $50–$150 delivery fee. Bulk topsoil typically runs $15–$50 per yard depending on type and market.

Settling: order more than the math

Loose topsoil compacts as it is graded, watered, and walked on — the in-place depth ends up less than the loose depth you ordered. A 10% settling allowance is standard, 15% on uneven sub-grade. Round up to whole yards from a bulk supplier; the extra half-yard is cheaper than a second delivery.

Worked examples

1. 10×10 bed at 6 inches: 100 sq ft × 6 in ÷ 324 = 1.85 cubic yards — order 2 yards.
2. 1,000 sq ft lawn at 4 inches: 1,000 × 4 ÷ 324 = 12.35 cubic yards — about 14 with a settling allowance.
3. 4×8 raised bed, 12 inches deep: 32 cu ft ÷ 27 = 1.19 cubic yards — order 1.5.
4. Topdressing 1,000 sq ft at 1/2 inch: 1,000 × 0.5 ÷ 324 = 1.54 cubic yards.

Weight and hauling

Moist screened topsoil weighs roughly 1.35 tons per cubic yard — a 2-yard order is about 2.7 tons, which exceeds many half-ton pickups' payload, so check before you haul it yourself. Delivery trucks carry far more: a six-wheeler about 8 yards, a tri-axle about 20. Wetter or compost-heavy soil weighs more than the planning factor.

Frequently asked questions

The rest of the landscaping order

Topsoil usually arrives with other materials — figure mulch for the beds, gravel for paths and drainage, and sod for the new lawn on top of it.