How Many Cubic Yards of Topsoil Do I Need? (Formula + Chart)
Order too little topsoil and the truck comes twice — two delivery fees. Order too much and you pay to dump the excess. The math is simple once you know it: area times depth, converted to cubic yards. Here is the exact method landscapers use.
The formula
Cubic yards = (length ft x width ft x depth inches) / 324
Example: a 20 x 15 ft lawn area, 4 inches deep: 20 x 15 x 4 / 324 = 3.7 cubic yards. Round up to 4 — settling always eats some. Our topsoil calculator does this instantly, handles multiple areas, and converts to bags if you are buying retail.
How deep should topsoil be?
- New lawn from seed: 4-6 inches. Grass roots need every one of them — see our grass seed calculator for how much seed the same area needs.
- Laying sod: 2-4 inches of prepared topsoil under the rolls. Pair with the sod calculator to order both in one trip.
- Topdressing an existing lawn: a quarter to half an inch only — more smothers the grass.
- Garden beds: 6-12 inches depending on what you grow. Root vegetables want the full 12.
- Filling low spots: measure the deepest point, and overfill 20% for settling.
Cubic yards vs bags: when to order bulk
One cubic yard = about 36 bags of the standard 0.75 cu ft size. Past 1 cubic yard, bulk delivery is almost always cheaper than bags — typical bulk topsoil runs $20-$50 per yard plus delivery, while the same yard in bags costs $80-$140. Under half a yard, buy bags and skip the delivery fee.
Weight matters: can your truck take it?
A cubic yard of dry topsoil weighs roughly 2,000 lbs — wet, up to 2,700. A half-ton pickup legally carries about half a yard. This is why delivery exists.
Topsoil, mulch, or compost?
Topsoil is structure — it is what things grow in. Compost is food — mix 20-30% into topsoil for beds. Mulch is cover — it sits on top to hold moisture and block weeds, and it is measured the same way; our mulch calculator handles that math. Planning a full yard makeover? The gravel driveway calculator uses the same area-times-depth method for hardscape, and the job costing calculator totals the whole project if you are quoting it as a contractor.
Frequently asked questions
How many cubic yards in a dump truck load?
Small single-axle trucks carry 5-7 yards; full-size dump trucks 10-14. If you need more than 7 yards, ask the supplier what their truck holds — one big load beats two small ones on delivery fees.
How much does a cubic yard of topsoil cover?
At 1 inch deep: 324 sq ft. At 4 inches: 81 sq ft. Divide 324 by your depth in inches.
Should I buy screened or unscreened topsoil?
Screened for lawns and beds — it is filtered of rocks and roots. Unscreened is cheaper and fine for filling deep holes where the top layer will be screened anyway.