Topsoil Calculator
Use this topsoil calculator to estimate how much topsoil you need in cubic yards or bags for lawns, beds, topdressing, raised-bed filling, and leveling work.
Choose the Right Soil for the Project
Depth is only half the decision. The other half is choosing a soil that fits the job: screened topsoil for lawns and leveling, compost blends for bed amendment, and raised-bed mix for deep vegetable or flower boxes.
Plain topsoil is not a one-size-fits-all product. It is often too dense for raised beds, and the label itself is not a regulated quality standard, so supplier quality still matters.
Soil Depth Guide
| Use Case | Depth | Notes |
|---|---|---|
| Lawn Topdressing | 1/4 inch | Thin layer before overseeding. Never exceed 1/2" — deeper smothers existing turf. |
| New Lawn / Seedbed | 4–6 inches | Full topsoil establishment over subsoil. Most projects are bulk-delivery scale. |
| Garden Bed Amendment | 2–3 inches | Added on top, then tilled into the top 6–8" of native soil. |
| Raised Bed Fill | 6–18 inches | Full bed depth — use a soil mix, not plain topsoil. See the 60/30/10 recipe. |
| Low Spots / Leveling | 1–2 inches | Topsoil finish layer. Use fill dirt for deeper structural fills. |
| Existing Garden Top-Up | 1–2 inches | Add around plants, gently work into the surface. |
Raised-Bed Mix Rule of Thumb
For new raised beds, start with a mix instead of plain soil. A common recipe is 60% topsoil, 30% compost, 10% soilless amendment. The calculator can break that down for you when you choose the Raised Bed Fill preset.
How the Math Works
Topsoil starts as an area-and-depth problem. The calculator converts your measurements into cubic feet and cubic yards, then into bags or tons using the density of the specific soil blend you picked.
Preset waste levels are different on purpose: topdressing is precise, new lawns and amendments need more tolerance, and low-spot fills need the most cushion because settling can hide material.
Worked Example: Raised Bed Fill
A 4 × 8 ft raised bed filled 12 inches deep, using the Raised Bed Fill preset with the standard 60/30/10 recipe.
- 1 Raised bed: 4 × 8 ft, 12" deep
- 2 Volume: 32 × (12/12) = 32 cu ft = 1.19 cu yd
- 3 Add 10% waste: 1.30 cu yd
- 4 Raised-bed recipe (60/30/10): topsoil 21.1 cu ft, compost 10.6 cu ft, soilless 3.5 cu ft
- 5 2 cu ft bags of raised-bed mix: ceil(35.2 / 2) = 18 bags
Pre-overseed lawn topdressing over 1,200 sq ft at 1/4 inch — the Lawn Topdressing preset with 5% overage.
- 1 Lawn: 1,200 sq ft, Lawn Topdressing preset
- 2 Depth: 0.25" (1/4" — standard pre-overseed topdress)
- 3 Volume: 1200 × (0.25/12) = 25 cu ft = 0.93 cu yd
- 4 Add 5% waste: 0.97 cu yd
- 5 1 cu ft bags: ceil(26.2 / 1) = 27 bags, or order 1.0 cu yd bulk
A 10 × 20 ft vegetable bed getting 2 inches of topsoil + compost blend tilled in — Garden Amendment preset.
- 1 Garden bed: 10 × 20 = 200 sq ft, Garden Amendment preset
- 2 Depth: 2" (added on top, tilled into top 6-8" of native soil)
- 3 Volume: 200 × (2/12) = 33.3 cu ft = 1.23 cu yd
- 4 Add 10% waste: 1.36 cu yd
- 5 1.5 cu ft bags: ceil(36.7 / 1.5) = 25 bags
Frequently Asked Questions
What's the difference between topsoil and garden soil? +
How many bags of topsoil are in a cubic yard? +
When is bulk topsoil cheaper than bags? +
Can I use topsoil in raised beds? +
Is "topsoil" a regulated quality standard? +
You May Also Need
Mulch Calculator
Calculate how much mulch you need in cubic yards and bags
Calculate →Sand Calculator
Plan sandbox, leveling, pool-base, and fill sand with bag and bulk buying options
Calculate →Drip Irrigation Calculator
Plan dripline, drip line length, emitter tubing, drippers, zones, and head assemblies for beds, rows, containers, and hedge runs
Calculate →Raised Bed Soil Cost Guide
How much it costs to fill raised beds: bulk vs bagged soil pricing and total costs by bed size
See Costs →