Topsoil Calculator
Estimate how many cubic yards, tons, or bags of topsoil you need for a new lawn, garden bed, or grading project.
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Loose, dry and wet soil can weigh very differently. Ask the supplier for a measured density when truck load or weight limits matter.
Topsoil Layer Depth
For healthy lawns and gardens, you need a nutrient-rich topsoil layer spread over your subsoil. Measure your yard area and select a depth (usually 4-6 inches for new lawns).
How to Use the Topsoil Calculator
Buying bags of dirt from the hardware store can get incredibly expensive. The calculator estimates the soil volume so you can compare bagged material with a bulk delivery.
- Measure the area: Input the length and width of the lawn, garden bed, or raised planter.
- Determine depth: Enter how many inches of soil you want to add. (4-6 inches is standard for new lawns).
- Set density: Use the supplier’s pounds per cubic foot when you need weight or bag comparisons.
- View the results: The calculator outputs cubic yards for bulk deliveries and 40 lb bags for store runs.
Topsoil Calculator Formula
Topsoil is sold by volume, so finding the cubic yardage is the most important step.
Step 1: Calculate Square Footage
Area = Length (ft) × Width (ft)
Step 2: Calculate Cubic Feet
Volume (ft³) = Area × (Depth in inches ÷ 12)
Step 3: Convert to Yards
Cubic Yards = Cubic Feet ÷ 27
Step 4: Convert to Weight and Bags
Pounds = Cubic Feet × Selected Density
US Tons = Pounds ÷ 2,000
40 lb Bag Equivalent = Pounds ÷ 40
Topsoil Example Calculation
You want to build a raised garden bed that is 8 feet long, 4 feet wide, and 12 inches deep.
- Area: 8 × 4 = 32 square feet.
- Depth: 12 inches is exactly 1 foot.
- Volume: 32 × 1 = 32 cubic feet.
- Convert to yards: 32 ÷ 27 = 1.18 cubic yards.
- Related material: If you need other materials for this project, check out our Mulch Calculator.
Conclusion: You need slightly more than 1 cubic yard of topsoil to fill the raised bed.
Tips for Landscaping with Topsoil
- Buy screened topsoil: Bulk topsoil is sold "screened" or "unscreened." Screened soil has been passed through a mesh to remove large rocks, roots, and clumps. It costs slightly more but is absolutely necessary for lawns and gardens.
- Check your truck capacity: A standard half-ton pickup truck (like an F-150 or Silverado 1500) can typically haul a maximum of 1 cubic yard of dry topsoil in the bed safely. If the soil is wet, haul less to avoid overloading your suspension.
- Account for settling: Freshly poured topsoil is loose and full of air. Once it rains, it will settle and compact by about 10-15%. Keep this in mind if you are trying to match the level of a driveway or sidewalk.
Transparent estimate
Accuracy, assumptions, and sources
Reviewed September 29, 2026
Volume, weight, bag count, and cost all use the same editable bulk-density assumption.
What this estimate assumes
- Default density is 75 lb/ft³.
- Bag count assumes a 40 lb bag and rounds up to a whole bag.
What it cannot know
- Moisture, organic content, screening, and settlement can substantially change weight and coverage.
Reference links
- NIST Guide for SI unit conversion
- Use the product label or a current supplier quote for coverage, density, and pack size
Found a questionable result? Report the inputs and result so the calculation can be rechecked.
Frequently Asked Questions
How many inches of topsoil do I need to plant grass?
If you are seeding a new lawn over poor quality subsoil, you should add a minimum of 4 to 6 inches of good quality screened topsoil.
How much does a cubic yard of topsoil weigh?
Weight varies with composition, moisture, and compaction. At the calculator’s 75 lb/ft³ starting density, one cubic yard weighs 2,025 lb, or about 1.01 US tons. Replace the density with the supplier’s value when payload matters.
How many 40 lb bags of topsoil make a cubic yard?
At 75 lb/ft³, one cubic yard is about 2,025 lb, equivalent by weight to roughly 51 forty-pound bags. Actual bag yield should come from the package because bagged volume and bulk density can differ.
What is the difference between topsoil and fill dirt?
Topsoil is the nutrient-rich, dark upper layer of soil that contains organic matter necessary for plant growth. Fill dirt is taken from deeper in the ground, lacks organic matter, and is used strictly for building up elevation or filling holes before topsoil is applied.