Area
Rectangle area = length × width
Circle area = π × (diameter ÷ 2)²
Triangle area = base × height ÷ 2
Free planning tool
Topsoil Calculator
Calculate how much topsoil you need for lawns, garden beds, raised beds, and landscaping areas. Add multiple areas, include optional extra material, and estimate bags, weight, or cost using your supplier’s information.
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Enter your project measurements
Measurements stay in this browser. No account, address, or location is required.
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Calculation details
Review each area, the units used, and where extra material or purchase rounding was applied.
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How topsoil volume is calculated
The calculator converts every area and depth to one internal unit before adding the volumes.
Volume
Area volume = area × depth
Base volume = sum of all area volumes
Adjusted volume = base volume × (1 + extra % ÷ 100)
Purchase quantity
Bags = round up(adjusted volume ÷ bag volume)
Bulk order = round up(adjusted volume ÷ increment) × increment
1 ft = 0.3048 m1 in = 25.4 mm1 yd³ = 27 ft³1 m³ = 1,000 L
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Worked example
This example demonstrates the formula. Its depth and extra percentage are examples, not recommendations.
Area10 ft × 20 ft
Depth3 in = 0.25 ft
Base50 ft³ = 1.851851… yd³
With 10% extra2.04 yd³
If the user separately selects a 0.5 yd³ supplier increment, the order quantity becomes 2.5 yd³. That rounding comes from the supplier increment, not from the volume formula.
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Important assumptions
This tool provides a planning estimate, not soil, gardening, engineering, or construction advice.
- Confirm your measurements, material parameters, and product label with your supplier.
- Density, moisture, compaction, settling, and packaging can change the amount delivered or used.
- The calculator applies only the extra percentage you enter. It does not infer compaction or settling.
- Prices come only from your entries and exclude delivery, tax, labor, and supplier fees.
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Cost and material estimate
Choose Bulk or Bags in the calculator to add supplier information without relying on national averages.
Bag counts round up only after all areas and extra material are combined. Bulk quantities round up only when you enter a supplier order increment. Leaving price or density blank hides cost or weight instead of showing a misleading zero.
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Frequently asked questions
Answers refer to this calculator’s formulas and behavior.
How do I calculate how much topsoil I need?
Measure each area, enter its shape and depth, and add the resulting volumes. The calculator performs those steps and shows the combined cubic yards or cubic meters.
How do I convert cubic feet to cubic yards?
Divide cubic feet by 27. One cubic yard is exactly 27 cubic feet.
Why does the calculator round bags up?
Bags are indivisible purchase units. The calculator adds all adjusted volume first, then rounds the final bag count up.
Can I calculate several lawn or garden areas together?
Yes. Add up to 20 areas. Each area can use its own shape, dimensions, name, and depth.
Why is estimated weight optional?
Weight depends on the supplier’s material density, moisture, and compaction. The calculator shows weight only when you enter a supplier density.
Does the calculator include compaction or settling?
No. It applies only the extra percentage you enter and does not infer a compaction or settling allowance.
Can I use this for raised beds?
You can use the calculator to estimate geometric volume. It does not recommend a soil mix or planting depth.
Does this include delivery fees or tax?
No. Estimated material cost uses only the supplier price you enter and excludes delivery, tax, labor, and other fees.
Formula reviewed: 2026-09-01
Exact length and volume conversions follow NIST definitions. Weight remains supplier-entered because soil density varies.