Quick answer: multiply area (ft²) by depth (in feet) and divide by 27 to get cubic yards. One cubic yard of topsoil covers 324 ft² at 1 inch, 162 ft² at 2 inches, 108 ft² at 3 inches, 81 ft² at 4 inches and 54 ft² at 6 inches. A 1,000 ft² lawn patch topped with 4 inches of soil needs 12.3 cubic yards. Order about 10% extra, because soil settles after it is spread (Topsoil.com).
The Topsoil Calculator does the arithmetic for any shape. Below are the formula, a coverage chart, and the weight numbers that matter for trucks and trailers.
The formula
Cubic feet = area (ft²) × depth (in) ÷ 12
Cubic yards = cubic feet ÷ 27
Coverage per cubic yard
| Depth | Area covered by 1 yd³ |
|---|---|
| 1 in | 324 ft² |
| 2 in | 162 ft² |
| 3 in | 108 ft² |
| 4 in | 81 ft² |
| 6 in | 54 ft² |
| 12 in | 27 ft² |
How deep should topsoil be?
It depends on the job, so treat these as typical starting points and ask a local nursery or your county extension office for local recommendations.
- Overseeding or patching a lawn: a thin layer of topsoil or compost, often 1 to 2 inches.
- Starting a new lawn on poor soil: the University of Maryland Extension’s new-lawn guide covers soil preparation and how much compost to mix in. It cites adding 1 to 2 inches of compost, which is about 3 to 6 cubic yards per 1,000 ft², to the soil before planting (1,000 ft² × 1 in ÷ 12 ÷ 27 = 3.1 yd³, and 2 in gives 6.2 yd³).
- Raised beds and gardens: usually filled with the full depth of the bed, commonly 6 to 12 inches.
Worked example 1: a lawn area
A 40 × 25 ft area (1,000 ft²) topped with 4 inches of topsoil:
- Cubic feet: 1,000 × 4 ÷ 12 = 333.3 ft³.
- Cubic yards: 333.3 ÷ 27 = 12.3 yd³.
- With 10% extra: 13.6 yd³, so order about 13.5 to 14 yards.
Worked example 2: a raised bed
A bed 4 ft × 8 ft filled 12 inches deep:
- Cubic feet: 4 × 8 × 1 = 32 ft³.
- Cubic yards: 32 ÷ 27 = 1.19 yd³.
- Weight: at moist topsoil’s roughly 2,400 lb per yard, the bed holds about 2,840 lb.
Raised-bed mixes are often blends of topsoil and compost rather than straight topsoil, so check what your supplier recommends.
How much does topsoil weigh?
Topsoil.com gives these approximate weights per cubic yard:
| Condition | Weight per yd³ |
|---|---|
| Dry | about 2,000 lb |
| Moist | about 2,400 lb |
| Saturated | about 2,800 lb |
That is roughly 1 to 1.4 tons per yard, and wet soil is much heavier than dry soil. A common pickup truck cannot safely carry more than a small number of yards of soil, so ask the truck’s payload rating and the supplier before you load. Many suppliers will deliver.
Bags or bulk?
Bagged topsoil makes sense for pots and tiny beds. Use bulk once you need more than a yard or two, but compare prices including delivery and minimums. Convert bag sizes with cubic feet: a yard is 27 ft³, so 54 bags of 0.5 ft³ equal one cubic yard.
Settling and slope
- Settling: order roughly 10% extra, as Topsoil.com advises.
- Slopes: on a steep bank, the surface area is bigger than the footprint, so measure along the slope.
- Existing soil: if you are adding soil on top of existing ground, only the new layer counts. Don’t bury grass or plant crowns: grade so the final level meets paths, patios and foundations correctly.
- Grade away from the house. Keep soil below siding and slope the ground away from the foundation, or ask a professional if you’re unsure.
Common mistakes
- Treating inches as feet. 4 inches is 0.333 ft.
- Ignoring settling. A perfectly measured pile ends up shorter once watered.
- Overloading a truck. Wet soil is heavy.
- Buying “topsoil” without checking what it is. Quality varies. Ask for a screened product and inspect a sample for rocks, clay lumps and debris.
- Forgetting that compost is usually mixed in, not stacked on top.
Frequently asked questions
How many square feet does a yard of topsoil cover?
81 ft² at 4 inches, 108 ft² at 3 inches, and 162 ft² at 2 inches.
How many cubic yards of topsoil for 1,000 sq ft at 6 inches?
1,000 × 0.5 ÷ 27 = 18.5 yd³.
How many bags of topsoil make a cubic yard?
27 ÷ bag size in ft³. With 0.75 ft³ bags that is 36 bags; with 1 ft³ bags, 27 bags.
Is topsoil measured by weight or volume?
Both. Suppliers sell by the cubic yard or by the ton, and weight per yard changes with moisture.
Can I use topsoil instead of garden soil or compost?
Usually not directly. Topsoil is a base material, and garden mixes combine topsoil with compost or sand. A soil test from your local extension office can tell you what your yard needs.
Sources
- Topsoil.com, >How much does a cubic yard of topsoil weigh?: weight by moisture, coverage per yard, ordering allowance.
- University of Maryland Extension, >Starting a New Lawn: soil preparation and compost guidance.
Planning estimates. Soil needs vary, so test your soil before big purchases.