How much topsoil do different jobs need?
- New lawn (seed or sod): Penn State Extension's lawn establishment guidance says a minimum of 4–6 in (firmed or settled depth) of good-quality topsoil is typically needed, ideally with 2 in of it blended into the top of the subsoil so you don't end up with a sharp layer that water and roots struggle to cross.
- New planting beds: plan on 6–12 in of improved soil, depending on what you grow and how poor the existing soil is.
- Raised beds: fill to the full bed height, less any drainage or filler layer.
- Leveling low spots in a lawn: spread thin layers so the grass can grow through. Many turf guides suggest about ¼–½ in at a time (approximate), repeated as the grass recovers.
How it's calculated
Volume = area × depth, raised by a settling allowance. Screened, fluffy topsoil settles once it's watered and walked on, so the default is 15% (rule of thumb). Weight = cubic yards × density. Published reference ranges put dry topsoil at about 1.0–1.3 tons per cubic yard, and wet topsoil can be well over 1.5 tons. The default is 1.1. For bags, the volume is divided by the bag size, and garden soil commonly comes in 0.75–2 ft³ bags.
With the defaults (20 × 10 ft at 4 in) the calculator returns 2.84 yd³ (76.7 ft³), about 3.12 tons.
Coverage per cubic yardCoverage per cubic metre
| Depth | Area per yd³ | yd³ per 1,000 ft² |
|---|---|---|
| 1 in | 324 ft² | 3.09 |
| 2 in | 162 ft² | 6.17 |
| 3 in | 108 ft² | 9.26 |
| 4 in | 81 ft² | 12.35 |
| 6 in | 54 ft² | 18.52 |
| 8 in | 41 ft² | 24.69 |
| 12 in | 27 ft² | 37.04 |
| Depth | Area per m³ | m³ per 100 m² |
|---|---|---|
| 2.5 cm | 40 m² | 2.5 |
| 5 cm | 20 m² | 5 |
| 7.5 cm | 13.3 m² | 7.5 |
| 10 cm | 10 m² | 10 |
| 15 cm | 6.7 m² | 15 |
| 20 cm | 5 m² | 20 |
| 30 cm | 3.3 m² | 30 |
Raised beds
For a raised bed, use the inside length and width and the depth you'll fill. A common 4 × 8 ft bed filled 10 in deep needs 26.7 ft³ before settling, or about 21 bags of 1.5 ft³ with the default 15% allowance. Many gardeners use a blend (topsoil plus compost) rather than straight topsoil. Calculate the total volume and split it by your mix ratio.
| Bed (inside) | Fill depth | Volume incl. 15% settling | 1.5 ft³ bags |
|---|---|---|---|
| 8 × 4 ft | 10 in | 1.14 yd³ (30.7 ft³) | 21 |
| 8 × 4 ft | 12 in | 1.36 yd³ (36.8 ft³) | 25 |
| 6 × 3 ft | 12 in | 0.77 yd³ (20.7 ft³) | 14 |
| 10 × 4 ft | 18 in | 2.56 yd³ (69 ft³) | 46 |
| Bed (inside) | Fill depth | Volume incl. 15% settling | 40 L bags |
|---|---|---|---|
| 2.4 × 1.2 m | 25 cm | 0.828 m³ (828 L) | 21 |
| 2.4 × 1.2 m | 30 cm | 0.994 m³ (994 L) | 25 |
| 1.8 × 0.9 m | 30 cm | 0.559 m³ (559 L) | 14 |
| 3 × 1.2 m | 45 cm | 1.86 m³ | 47 |
Worked examples
New lawn area, 50 × 40 ft, 4 in topsoilNew lawn area, 15.2 × 12.2 m, 10.2 cm topsoil
Length 50 ft · Width 40 ft · Depth 4 in · Soil density 1.1 tons/yd³ · Settling allowance 15 % · Waste / overage 0 % · Bag size 0.75 ft³Length 15.24 m · Width 12.19 m · Depth 10.2 cm · Soil density 1.31 t/m³ · Settling allowance 15 % · Waste / overage 0 % · Bag size 21.2 L
- Volume: 28.4 yd³ (766.7 ft³)Volume: 21.71 m³
- Weight: 31.23 tonsWeight: 28.34 tonnes
Vegetable beds, 30 × 10 ft, 6 inVegetable beds, 9.14 × 3.05 m, 15.2 cm
Length 30 ft · Width 10 ft · Depth 6 in · Soil density 1.1 tons/yd³ · Settling allowance 15 % · Waste / overage 0 % · Bag size 0.75 ft³Length 9.14 m · Width 3.05 m · Depth 15.2 cm · Soil density 1.31 t/m³ · Settling allowance 15 % · Waste / overage 0 % · Bag size 21.2 L
- Volume: 6.39 yd³ (172.5 ft³)Volume: 4.88 m³
- Weight: 7.03 tonsWeight: 6.38 tonnes
Buying good topsoil
- Ask whether it's screened. Screened soil has stones, roots and clods removed and spreads much more easily.
- Look at it, or ask for a sample. Good topsoil is crumbly and dark, and smells earthy. Heavy clay lumps or construction debris are red flags.
- Test your existing soil. Penn State recommends a soil test before establishing a lawn, so lime and fertilizer match what the soil actually needs. University labs offer low-cost tests.
- Don't spread wet soil. Working wet soil damages its structure, and the extension guides advise against tilling when it's wet.
Bulk delivery vs. bags
For anything bigger than a few raised beds, bulk delivery is usually cheaper and much less work than dozens of bags. Two cubic yards is 54 ft³, which is 72 bags of 0.75 ft³. Bulk soil can weigh more than 1 ton per yard, so it's beyond most car trailers. Have it tipped as close to the work area as the truck can safely reach, on a tarp if it's going on a lawn.
Common mistakes
- Ordering the finished depth with no settling allowance. Penn State's 4–6 in lawn figure is a firmed or settled depth. Loose soil settles, so you need more than the finished depth suggests.
- Dumping a thick layer over compacted subsoil. Water perches at the boundary. Loosen the subsoil and blend in the first couple of inches.
- Raising soil against the house. Keep the finished grade below siding and sloping away from the foundation.
- Smothering trees. Adding several inches of soil over tree roots can harm them. Ask an arborist before regrading under a tree.
Allow for settling
Loose soil from a truck or bag settles once it's firmed, watered and rained on. Penn State's 4–6 in recommendation for lawns refers to the firmed or settled depth, so spread a bit higher than your target, then firm it with a light roller or a soaking and check the depth again before you seed or sod. That's what the calculator's settling allowance covers. The default is 15%, a planning assumption rather than a measured figure, so raise it for very loose or fluffy soil and lower it for soil that's already been screened and firmed. If you're filling against a foundation, keep the finished grade sloping away from the house and below the siding.
Checked against
Each case below is re-run against the calculator by our automated test suite.
| Case | Our result | Checked against | Result |
|---|---|---|---|
| 20 × 10 ft, 4 in deep, no settling or waste: volume | 2.47 yd³ (66.7 ft³) | Hand calculation | Match |
| Case | Our result | Checked against | Result |
|---|---|---|---|
| 6.1 × 3.05 m, 10.2 cm deep, no settling or waste: volume | 1.89 m³ | Hand calculation | Match |
Frequently asked questions
How much topsoil do I need for sod?
Penn State Extension recommends at least 4–6 in of quality topsoil for lawn establishment. For 1,000 ft² at 4 in, that is about 12.3 yd³ before settling.
How much is a yard of topsoil in tons?
Roughly 1.0–1.3 tons when dry, more when wet (published reference ranges).
How much does a yard of topsoil cover?
About 81 ft² at 4 in, 162 ft² at 2 in and 54 ft² at 6 in.
How much topsoil to level a lawn?
Measure the low areas and their average depth. Spread thin layers, often around ¼–½ in at a time, so the grass can grow through.
Sources & assumptions
The results are planning estimates, and the cost figures only use prices you enter. Product yields, densities and coverage rates vary, so check the label or ask your supplier, and follow local codes. Figures marked "approximate" or "rule of thumb" are general practice, not exact standards.
- Penn State Extension: Lawn Establishment
- Inch Calculator: weight per cubic yard of landscape materials (published reference ranges)
- Purdue Extension: Establishing a Lawn From Sod (AY-28-W)
See how we calculate and test our formulas and the changelog. Last updated 2026-10-08.
Reviewed by the MaterialWhiz Editorial Team. This estimate uses the assumptions shown in the calculator. Review the result against your supplier's product coverage and site conditions. Last reviewed: October 10, 2026. See how we calculate · Report a correction.