How to Use This Calculator
- 1Measure your area
Select your shape — rectangle, circle, or triangle — and enter the dimensions in feet. The preview updates in real time to show the coverage area.
- 2Decide on depth
Choose your desired topsoil depth. Use 3–4 inches for a new lawn, 6–8 inches for a vegetable bed, or 2–3 inches for general landscaping and topdressing.
- 3Choose topsoil type
Select the soil type that matches your project. Each type has a real density value that affects the weight calculation used for truck load planning.
- 4Calculate volume
Read the cubic yard and cubic foot results. One cubic yard covers approximately 108 sq ft at 3 inches deep. Use cubic yards for bulk orders and cubic feet for bagged purchases.
- 5Allow for compaction
Add 10% to your order to account for settling. Fresh topsoil compresses 10–15% after watering as air pockets collapse and particles realign.
Key Terms
Frequently Asked Questions
How deep does topsoil need to be?
A minimum of 3–4 inches is required for a new lawn from seed. For vegetable gardens, 6–8 inches allows most vegetables to develop full root systems. For raised beds, 12 inches is ideal. Topdressing an existing lawn uses only ¼–½ inch blended into the existing surface.
What is the best topsoil mix for planting?
A blend of 60–70% screened topsoil and 30–40% compost is ideal for most planting applications. The compost adds nutrients and improves drainage. For vegetable gardens, some growers use a mix of 1/3 topsoil, 1/3 compost, and 1/3 coarse perlite or sand for maximum drainage and aeration.
Should I till before adding topsoil?
Yes, for new installations. Till or loosen the existing soil 4–6 inches deep before adding topsoil. This breaks up compaction and allows the new topsoil to integrate with the existing soil rather than sitting on top as a separate layer. A hard transition layer between old and new soil can trap water and harm roots.
Is bagged topsoil or bulk topsoil better?
Bulk topsoil is significantly cheaper for quantities above 1–2 cubic yards. Bags ($5–8 each for 1 cu ft) cost $135–216 per cubic yard — vs. bulk at $30–55 per cubic yard plus $50–100 delivery. Use bags for tiny projects under 0.5 cubic yards or where a delivery truck cannot access your site. Always check the quality of bulk topsoil before delivery — request a sample or site visit.
How to Use This Calculator
Measure Your Area
Choose a shape (rectangle, circle, or triangle) and enter your dimensions in feet. The live SVG preview scales as you type.
Set Depth & Soil Type
Click a depth chip for instant results. Select your soil type — each has a real density value that affects the weight estimate.
Add Wastage Buffer
Topsoil settles 10-15% after watering. The +10% buffer is the industry standard for accurate ordering.
Plan Multi-Zone Projects
Use the Project Planner tab to add multiple beds or areas and get one combined order total with an export CSV.
Formulas & Methodology
Key Terms
- Cubic Yard
- A 3×3×3 ft volume = 27 cubic feet. One cubic yard covers ~108 sq ft at 3 inches deep.
- Topsoil
- The uppermost layer of native soil, rich in organic matter. Screened topsoil has been sifted to remove rocks and debris.
- Fill Dirt
- Subsoil with no organic content. Used only for structural grading — never for planting areas.
- Compost
- Fully decomposed organic matter. Lightweight (1,100 lbs/cy), nutrient-rich. Best blended with topsoil at 20-30%.
- Settling
- Fresh topsoil compresses 10-15% after watering due to air pockets. Order extra to account for this.
- Bulk Density
- The weight of soil per unit volume. Varies by moisture content and composition — affects delivery truck capacity.
Real-World Examples
4×8 ft Vegetable Bed at 12″ deep
Area: 32 sq ft · Depth: 1 ft
32 × 1 ÷ 27 = 1.19 cy (before buffer)
With 10% buffer → order 1.3 cy
~$58 at $45/cy · ~35 bags of 1 cu ft
40×30 ft Backyard at 3″
Area: 1,200 sq ft · Depth: 0.25 ft
1,200 × 0.25 ÷ 27 = 11.1 cy
With 10% buffer → order 12.2 cy
~$549 at $45/cy · Full truckload (≈13 cy)
12 ft diameter circle at 4″
Area: π × 6² = 113 sq ft
113 × 0.333 ÷ 27 = 1.39 cy
With 10% buffer → order 1.53 cy
~$69 at $45/cy · ~42 bags of 1 cu ft
Frequently Asked Questions
How many cubic yards of topsoil do I need?
Multiply your area in square feet by the depth in feet, then divide by 27. For a 20×15 ft area at 3 inches (0.25 ft): 20 × 15 × 0.25 ÷ 27 = 2.78 cubic yards. Add 10% for settling = order 3.1 cubic yards. This calculator does all that instantly.
Is bulk topsoil or bags cheaper?
Bulk delivery wins above 2 cubic yards. Bags at $5-8 each (1 cu ft) = $135-216 per cubic yard. Bulk topsoil costs $30-55 per cubic yard plus a $50-100 delivery fee. For 5 cy: bags cost $675-1,080 vs bulk $200-375 delivered — a $300-700 saving. Use bags only for tiny projects, tight-access areas, or when delivery isn't available.
How deep should topsoil be for a lawn?
A minimum of 4 inches of quality topsoil is needed for a healthy lawn. 6 inches is the professional recommendation for drought tolerance and recovery from damage. For topdressing an existing lawn, just ¼-½ inch is used. Grass roots in compacted or shallow soil only reach 1-2 inches deep, making the lawn fragile.
What does topsoil weigh per cubic yard?
Weight varies by type: Garden mix ≈ 2,200 lbs/cy, screened topsoil ≈ 2,000 lbs/cy, fill dirt ≈ 2,700 lbs/cy, sandy loam ≈ 1,900 lbs/cy, compost ≈ 1,100 lbs/cy, clay mix ≈ 2,800 lbs/cy. Wet soil can be 15-20% heavier. A standard dump truck carries 10-14 cubic yards (10-19 tons depending on soil type).
What is settling and how much extra should I order?
Topsoil settles 10-15% after watering and natural compaction — air pockets compress and particles realign. If you order exactly 3 inches, you may end up with 2.5-2.7 inches. Always order 10% more than calculated. If you're filling against a structure or for drainage grading, order 15% extra.
What is the difference between topsoil, garden mix, and fill dirt?
Topsoil is the upper layer of native earth with some organic matter — good for general landscaping. Garden mix is a blended product (topsoil + compost + sometimes sand) with improved drainage and higher nutrient content — best for planting beds. Fill dirt is subsoil with no organic content — used only for structural fill or grading. Never use fill dirt where plants will grow.
How do I calculate topsoil for a circle or triangle area?
Circle: Area = π × (diameter ÷ 2)². Triangle: Area = ½ × base × height. Then multiply by depth in feet and divide by 27. This calculator handles all three shapes automatically — just click the shape chip and enter your dimensions.
Can I use compost instead of topsoil?
Not as a direct replacement. Pure compost is too light and fluffy — it settles dramatically (up to 40%), burns roots if used in thick layers, and doesn't provide structural support. The ideal mix is 70% topsoil + 30% compost blended together. Use compost as an amendment to improve topsoil, not replace it.
How many bags of topsoil per cubic yard?
1 cubic yard = 27 cubic feet. For 1 cu ft bags: you need 27 bags. For 2 cu ft bags: 13-14 bags. For 0.75 cu ft bags (common at garden centers): 36 bags. At $5-8 per 1 cu ft bag, that's $135-216 per cubic yard — much more expensive than bulk above 2-3 cubic yards.
How do I test topsoil quality before buying?
Request a soil test from your supplier or send a sample to your state's cooperative extension lab ($15-25). Key metrics: pH 6.0-7.0, organic matter 3-5%, texture classification (loam ideal). On-site: grab a handful — it should form a clod that breaks apart when poked, smell earthy, be dark brown, and be free of rocks and debris. Avoid light gray or pale brown topsoil (low organic matter).
Recommended Topsoil Depths
| Application | Depth | Notes |
|---|---|---|
| Lawn topdressing | ¼–½″ | Annual maintenance — blend with existing soil |
| Lawn overseeding | 1–2″ | Mix into top 4–6″ of existing soil |
| New lawn from seed | 3–4″ | Minimum for healthy root development |
| Vegetable garden bed | 6–8″ | Deep enough for most vegetable roots |
| Raised garden bed | 12″ | Full depth for maximum yield potential |
| Grade change / fill | As needed | Compact in 6″ lifts; allow 10–15% settling |
| Tree planting backfill | 18–24″ | Diameter at least 3× the root ball width |