Topsoil Calculator
Calculate the cubic yards of topsoil needed to fill, top-dress, or grade a rectangular area to a specified depth. Use it for new lawn installation, raised bed filling, and lawn renovation projects before ordering bulk soil.
Last updated: May 2026
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About this calculator
The formula is: topsoilYards = (length × width × (depth/12)) / 27, where length and width are in feet, depth is in inches, /12 converts inches to feet, and /27 converts cubic feet to cubic yards (1 yd³ = 27 ft³). The result is bulk topsoil volume. Standard topsoil application depths: 1–2 inches for top-dressing existing lawns (improves soil quality without smothering grass); 4–6 inches for new lawn installation over poor subsoil (deep enough for grass root establishment); 8–12 inches for raised vegetable beds (typical garden bed depth); 4–6 inches mixed with compost for new ornamental beds; 6+ inches for grading and leveling severely compacted or poor-quality ground. Edge cases: zero values produce zero output; non-rectangular shapes require breaking into rectangles or using shape-specific area formulas. Bulk topsoil costs $20–$50/cubic yard delivered (varies widely by region); much cheaper than bagged topsoil ($60–$100/yd³ equivalent) for jobs over 2 cubic yards. Quality matters substantially: avoid "fill dirt" (unscreened subsoil with rocks and debris); use "screened topsoil" or "garden soil mix" for plantings; look for dark crumbly material with no obvious clay clods or rocks. A pickup truck (8-ft bed) holds 1.5–2 yd³ filled level; bigger jobs require delivery from a landscape supplier ($50–$150 delivery fee in most metros). One cubic yard covers: 324 sq ft at 1 inch; 162 sq ft at 2 inches; 108 sq ft at 3 inches; 81 sq ft at 4 inches; 54 sq ft at 6 inches; 27 sq ft at 12 inches. For raised beds, multiply width × length × depth in feet for cubic feet, then divide by 27 for yards. For irregular shapes, sum rectangular sub-areas or approximate with averages.
How to use
Example 1 — New lawn installation over poor subsoil. 50 ft × 40 ft area needing 4 inches of topsoil before sodding. Enter length 50, width 40, depth 4. Result: (50 × 40 × (4/12)) / 27 = (2000 × 0.333) / 27 = 666.67 / 27 ≈ 24.7 cubic yards. ✓ Order 25 yards from a landscape supplier ($600–$1,000 delivered depending on region). Delivery typically arrives in dump truck loads of ~10 yards each; arrange for staging area off the lawn (driveway or street) to avoid compacting the prepared ground. Example 2 — Raised vegetable beds. Three raised beds: each 4 ft × 8 ft × 12 inches deep. Total volume per bed = 4 × 8 × 1 = 32 cubic feet. Times 3 beds = 96 cubic feet. Convert to yards: 96/27 ≈ 3.56 cubic yards. Enter length 24 (3 beds × 8 ft), width 4, depth 12. Result: (24 × 4 × 1) / 27 = 96/27 ≈ 3.56 cubic yards. ✓ Order 4 yards of garden soil mix (topsoil blended with compost, ideal for raised beds). For beds, do not pack the soil — fill loosely; it will settle 10–20% in the first few months as organic matter decomposes, requiring a topup at the start of season 2.
Frequently asked questions
What's the difference between topsoil, fill dirt, and garden soil?
These terms vary regionally but generally: Topsoil is the upper 4–12 inches of natural soil, containing organic matter and microbial life, capable of supporting plant growth. Screened topsoil has been sifted to remove rocks, sticks, and large debris. Fill dirt is subsoil or excavated material from below the topsoil layer — used for grading and filling holes; not suitable for plantings because it lacks organic matter and may compact severely. Garden soil mix (often called "raised bed mix" or "planting mix") is topsoil blended with compost, peat, and sometimes sand or perlite for specific applications; more expensive but optimized for plant growth. Quality varies by supplier and region — sandy topsoil from one area differs dramatically from clay topsoil from another. For lawn installation, basic screened topsoil works fine. For raised vegetable beds and intensive planting, use a garden soil mix or amend basic topsoil with 30–50% compost. Always inspect before delivery: ask for a sample, check for weed seeds (especially nutsedge, crabgrass), and avoid soil from new construction sites (often contaminated with construction debris).
How deep should I apply topsoil for a new lawn?
Minimum 4–6 inches over decent subsoil; 6–8 inches over poor or compacted subsoil. Grass roots need 4 inches of quality soil to establish; less than that produces shallow-rooted lawns prone to drought stress, disease, and traffic damage. The "good" subsoil reference: if the existing subsoil drains well (water disappears from a 12-inch hole within 24 hours), it supports root extension into the deeper soil, and 4 inches of topsoil is enough. The "poor" subsoil reference: heavy clay or compacted ground where water sits, or rocky/sandy soil with no organic matter — these need 6–8 inches of imported topsoil plus tilling into the top 2 inches of existing soil for transition zone. For new construction sites with severely disturbed soil, 8–12 inches of imported topsoil mixed with compost provides the long-term foundation for healthy lawn. Skipping adequate topsoil is the #1 cause of poor new lawn establishment — cheaper to do it right at install than to fight problems for 10 years.
What soil mix is best for raised beds?
Standard "raised bed mix" or DIY ratio: 50–60% high-quality topsoil + 30–40% compost + 10–20% perlite or coarse sand for drainage. Adjust for crop type: vegetables tolerate slightly heavier mixes (more topsoil); root crops (carrots, beets, parsnips) need lighter mixes with more compost and sand for easy root penetration; flowers and ornamentals work in standard mix. Mel's Mix (from "Square Foot Gardening"): 1/3 peat moss + 1/3 compost + 1/3 vermiculite; works well but expensive and the peat is unsustainable (better alternatives: coconut coir). For deep beds (12+ inches): "hugelkultur" method places branches and logs at the bottom (slow decomposition retains moisture); fills the top 12 inches with garden mix. For bed amendments year over year: add 2–3 inches of fresh compost annually, mixed into the top 6 inches; replenish 10–20% annual loss from settling and organic decomposition. For balconies and rooftops, lightweight container mix (peat + perlite + coir) is preferred over heavy topsoil for structural reasons.
What are the most common topsoil mistakes?
The biggest is buying fill dirt thinking it's topsoil — fill dirt does not support plant growth and produces failed installations. Always verify "screened topsoil" and inspect a sample before bulk delivery. The second is under-ordering depth; 2 inches of topsoil over compacted clay subsoil produces poor results, while 6 inches solves most problems. The third is buying poor-quality topsoil with weed seeds (especially Bermuda grass, nutsedge, crabgrass) that contaminate the new lawn or bed; ask for weed-free certification or buy from established suppliers. The fourth is not tilling existing soil before adding topsoil; topsoil layered on compacted ground creates a perched water table that suffocates roots. Till the top 2 inches of existing soil into the imported topsoil for transition. The fifth is over-compacting the topsoil during installation; rolling and walking on freshly delivered soil destroys the structure. Spread loosely and rake smooth; do not compact except for final grading. The sixth is ordering topsoil based on simple length × width without depth math — many homeowners under-order by 50%+. The seventh is forgetting that bulk soil settles 10–20% in the first months — order extra for raised beds, and plan to topup as it settles. The eighth is installing in poor weather; muddy soil from rain is heavy and difficult to work, and dry soil during drought is dusty and hard to grade.
When should I not use bulk topsoil?
Skip it for small jobs (under 1 cubic yard, ~30 cubic feet) where bagged garden soil from a hardware store is more convenient and cost-comparable. It is the wrong tool for container gardening and pots where container-specific lightweight mixes outperform; never use topsoil in containers (drainage and weight issues). Do not use it for terrarium and indoor plants; use sterile potting mix instead. For acid-loving plants (azaleas, blueberries, rhododendrons, hydrangeas) where pH is critical, use acidic peat-based mixes rather than generic topsoil which is typically neutral to slightly alkaline. For desert and xeriscape plantings using cactus and succulents, use sand-based fast-draining mixes; topsoil retains too much water for these species. For native plantings where local soil works fine, importing topsoil disturbs the natural soil structure and may introduce non-native organisms; native plants thrive in native soil. For organic certification programs, topsoil source matters and must comply with USDA Organic input requirements; verify supplier certification. And for sites with potential soil contamination concerns (former industrial use, near busy roads), test before assuming "bulk topsoil" is appropriate; some commercial topsoils come from sites with heavy metal residues that fail to meet residential soil standards.