You're grading your yard, building a raised garden bed, or filling a low spot, and you need to know: how many cubic yards of topsoil or fill dirt do I need?
Soil is measured in cubic yards-the standard delivery unit. One cubic yard covers 324 square feet at 1-inch depth. Getting this right prevents multiple trips to buy more or overpaying for excess material you don't need. Our soil calculator converts your area and desired depth into exact cubic yards needed.
What This Calculator Does
This tool calculates soil volume based on the area you're covering and the depth of soil you want to add. You input length and width in feet, specify depth in inches (typical is 2โ12 inches depending on the project), and the calculator converts to cubic yards. It includes a 10% waste factor for settling, spreading, and compaction. The result is the exact amount to order from a landscape supplier.
How to Use This Calculator
Step 1: Measure the length and width of the area in feet. For multiple sections, calculate each separately and sum the results.
Step 2: Decide on depth. Topsoil for gardens: 6โ12 inches (better for root growth, more expensive). Fill for raising grade: 2โ4 inches (cheaper, just raising level). Raised garden beds: 8โ12 inches minimum. Lawn renovation: 2โ3 inches.
Step 3: Choose soil type. Topsoil (dark, nutrient-rich, best for gardens). Fill dirt (cheaper, less organic matter, for grading). Compost (expensive, rich in nutrients, for amending beds). Specify if ordering.
Step 4: Enter measurements. The calculator instantly shows cubic yards needed.
Step 5: Order from a landscape supplier. Soil is sold by the cubic yard. Trucks typically deliver 5โ15 cubic yards per load.
The Formula Behind the Math
The calculation is:
Volume (cubic yards) = (Length ft ร Width ft ร Depth inches รท 12) รท 27
Adjusted for waste: Volume ร 1.10
Let's work through a practical example: raising the grade of a yard area 30 feet ร 40 feet by 4 inches using fill dirt.
Our calculator does this instantly.
Small Raised Garden Bed (DIY Height)
A raised bed 4 feet wide ร 8 feet long ร 12 inches tall (standard height for comfortable gardening).
A single raised bed is a manageable DIY project. Bulk topsoil is overkill for one small bed; bagged soil is convenient.
Large Garden Area (Multiple Raised Beds, 8 Inches Deep)
A garden plot with multiple raised beds totaling 200 square feet, 8 inches deep quality topsoil.
Five cubic yards of topsoil costs roughly $50โ100 from a supplier (much cheaper than bagged equivalent at home centers). This is a garden that will grow excellent vegetables or flowers.
Lawn Renovation (Whole Yard, 3-Inch Top Dressing)
A 6,000-square-foot yard (roughly 0.14 acres, typical residential lot) getting a 3-inch topsoil top-dressing to improve soil quality and seed new grass.
A full yard renovation like this needs roughly 60 cubic yards. This is a major project requiring 4โ6 truckloads (depending on truck capacity). Professional grading contractors often handle this scale.
Grading Project (Low Spot Correction, 2 Inches Average)
A residential property with a low area (100 ร 100 feet) that collects water after rain. Adding 2 inches of fill to raise the grade and improve drainage.
A grading project of this scale needs roughly 68 cubic yards, or 5โ7 truckloads. Requires heavy equipment (grader, compactor) for proper installation-this is a contractor project.
Tips and Things to Watch Out For
Soil compacts and settles after installation-plan for settling. Loose soil compresses to about 80% of its original volume after settling with water and traffic. If you need a permanent height increase, order 20% extra to account for this. For gardens, slight settling is acceptable.
Topsoil quality varies dramatically-specify what you want. Premium topsoil is dark, rich, and weed-free (screened). Bulk topsoil from suppliers may contain rocks, clay, or weed seeds. Ask for screened topsoil with organic matter content (at least 5โ10% for gardens). Cheap topsoil is often subpar.
Fill dirt and topsoil are not interchangeable. Fill dirt is cheaper but has no organic matter-it's dense clay or sandy material used just for raising grade. Topsoil is nutrient-rich and dark, ideal for plants. For gardening, don't cheap out on topsoil; for mere grading, fill dirt is fine.
Always order 10โ15% more material than your calculation to account for waste, cuts, breakage, and measurement errors. Soil settles and compacts after spreading. Measurement errors are common over large areas. Order extra to ensure coverage and account for settling.
Compost added to fill dirt or poor topsoil improves it significantly. If you're on a budget, order fill dirt and amend it with 10โ20% compost by volume. A 60/40 or 70/30 mix of soil to compost is excellent for gardens and costs less than pure premium topsoil. This is a smart compromise.
Check drainage before and after adding soil. If the area drains poorly before adding soil, adding soil won't fix it. Improve drainage by grading slightly away from structures, adding perforated drainage pipes if needed, or creating swales. Adding soil to a poor-drainage area just delays the problem.
Frequently Asked Questions
How much topsoil do I need for a 100 square foot garden?
At 8 inches depth: (100 ร 8 รท 12) รท 27 = 2.47 cubic yards โ 2.5 cubic yards. At 12 inches: roughly 3.7 cubic yards. Most gardeners want 8โ12 inches of quality topsoil.
What's the difference between topsoil, fill dirt, and compost?
Topsoil: nutrient-rich dark soil, ideal for gardens. Fill dirt: dense, inorganic, used for grading-cheap. Compost: decomposed organic material, very nutrient-rich, expensive, usually mixed in rather than used alone. For gardens: topsoil or topsoil + compost. For grading: fill dirt.
Can I use my native soil instead of buying topsoil?
Maybe. If your native soil is dark and nutrient-rich (or tests well), yes. If it's clay, sandy, or depleted, no-it will produce weak plants. A soil test (cheap, from your county extension) tells you. Usually, it's worth buying quality topsoil for gardens.
How many cubic yards is a ton of soil?
Topsoil weighs roughly 1.3โ1.5 tons per cubic yard (depending on moisture). So 1 ton โ 0.7 cubic yard. If someone quotes soil in tons, convert: multiply tons by 0.7 to get cubic yards. Suppliers use both measurements; know which you're getting.
Should I amend native soil instead of replacing it?
Yes, if native soil is decent. Amending (mixing in 3โ6 inches of compost or topsoil) improves it without full replacement. This is cheaper than replacing 12 inches of soil throughout. For raised beds or very poor native soil, replacement is better.
How much does soil cost?
Fill dirt: $5โ15 per cubic yard. Topsoil: $20โ50 per cubic yard (varies widely by quality). Compost: $40โ100+ per cubic yard. Get 3 quotes; prices vary significantly by region and supplier. Bulk orders often get discounts.
Can I use soil from my property when grading?
Yes, if it's quality soil and you have excess from excavation or digging. But often, excavated soil is clay, subsoil (poor quality), or mixed with rocks. Professional grading contractors test soil and import better material if needed. Don't assume your excavated soil will work.
How deep should topsoil be for grass?
For new lawn seeding: 4โ6 inches minimum, 8 inches ideal. For existing lawn renovation: 2โ3 inches top-dressing. For vegetables or gardens: 8โ12 inches. Purpose determines depth. Short: cost-saving grading. Deep: excellent plant growth.
Related Calculators
Use the square footage calculator to measure areas precisely. The mulch calculator helps if you're combining soil with mulch for raised beds. The compost calculator (if available) estimates amendment needs for improving existing soil.