Use this topsoil calculator to find how many cubic yards, tons, or bags of soil you need. It works two ways: ground areas (lawns, beds, grading) where picking your project sets the right depth automatically, and raised beds, where you enter the box dimensions and how many you are filling. It also splits a blended mix into its parts and shows what a layered fill saves you.
Area: 0 sq ft
Soil type, settling & prices — adjust defaults
How to calculate topsoil by hand
cubic yards = length (ft) × width (ft) × depth (ft) ÷ 27Worked example: a 30 ft × 20 ft area seeded at 5 inches. Depth is 5 ÷ 12 = 0.417 ft. Volume: 30 × 20 × 0.417 = 250 cubic feet ÷ 27 ≈ 9.26 cubic yards. At about 1.1 tons per yard, that is roughly 10 tons — plan for a full dump-truck delivery rather than bags.
How deep should topsoil be?
| Project | Recommended depth | Yards per 1,000 sq ft |
|---|---|---|
| Top dressing existing lawn | 1" | 3.1 |
| New sod lawn | 3–5" | 9.3–15.4 |
| New lawn from seed | 4–6" | 12.3–18.5 |
| Vegetable garden bed | 8–12" | 24.7–37.0 |
| Raised planting bed | 12–18" | 37.0–55.6 |
Grass roots need at least 4 inches of quality soil to establish a drought-resistant lawn; 6 inches is better where summers are hot. For deep beds, many gardeners save money by filling the bottom half with cheaper fill dirt or compostable material and reserving screened topsoil or garden soil for the top 6–8 inches.
Do not fill a raised bed entirely with good soil
This is the most expensive mistake in raised-bed gardening. A single 8 × 4 ft bed filled 18 inches deep needs about 1.8 cubic yards of soil. At garden-mix prices that is real money — and it is money spent on soil that nothing will ever root into.
Most vegetable roots live in the top 8–12 inches. Below that, the bed only needs to drain and hold moisture. So fill the bottom half with something cheap:
- Fill dirt or unscreened topsoil — a third to half the price of garden mix
- Rough compost, leaves, grass clippings — free, and it breaks down into good soil
- Logs and branches (hügelkultur) — free, holds water like a sponge, feeds the bed for years
Switch the calculator to Raised beds and pick a fill strategy — it splits the order into quality soil and cheap bottom fill, and warns you if the good layer drops below the 6 inches that even shallow-rooted crops need. Expect the bed to settle 20% in the first season, which the calculator already allows for.
Blended mixes, split into parts
Few beds get straight topsoil. Common blends are 60/40 topsoil and compost for garden beds, or the classic Mel’s Mix — equal thirds compost, peat moss or coir, and vermiculite. Ordering these means knowing the volume of each component, not just the total. Pick a blend in the calculator and it breaks the order down by material, in both cubic yards and bag counts.
Topsoil vs garden soil vs fill dirt
| Topsoil | Garden soil | Fill dirt | |
|---|---|---|---|
| What it is | Screened natural surface soil | Topsoil + compost blend | Subsoil, little organic matter |
| Best for | Lawns, grading, top dressing | Planting beds, raised beds | Raising grade, filling holes |
| Relative cost | $$ | $$$ | $ |
FAQ
How much does a yard of topsoil weigh?
About 2,000–2,200 lbs dry (1.0–1.1 tons); wet or clay-heavy soil can hit 3,000 lbs.
How many bags in a yard?
~36 bags at 40 lb (0.75 cu ft) or 27 bags at 1 cu ft. Past ~10 bags, bulk wins on price.
How much for a new lawn?
4–6" for seed, 3–5" for sod. A 1,000 sq ft lawn at 5" needs ~15.4 yards.
Topsoil vs garden soil vs fill dirt?
Topsoil = screened natural soil; garden soil = topsoil + compost for planting; fill dirt = cheap subsoil for raising grade only.
Does topsoil settle?
Yes, 15–20% after watering. Order extra if final grade matters.