Topsoil Calculator
Calculate how much topsoil you need from the area and finished soil depth, with an allowance for settling and waste.
What is the topsoil calculator?
Calculate how much topsoil you need from the area and finished soil depth, with an allowance for settling and waste.
How to use the calculator
Enter the dimensions of the area and the target depth of soil. If you are filling an irregular bed, split it into smaller rectangles and add their areas before using the calculator.
How to calculate topsoil
Convert the depth to feet, multiply area by depth, and divide by 27 to get cubic yards. For bagged soil, divide cubic feet by the actual cubic-foot volume printed on the bag.
Accounting for settling
Soil can settle after placement, especially when filling beds or low areas. Your allowance should reflect the condition of the soil and the finished grade you need.
Topsoil for lawns and garden beds
The required depth depends on the project. Lawn establishment, raised beds, grading, and planting beds have different needs. Use a project-specific depth rather than a universal number.
Bulk delivery planning
Bulk topsoil is usually quoted in cubic yards. Confirm whether the supplier uses loose volume, whether the soil is screened or blended, and whether delivery fees are separate.
How to improve the accuracy of your estimate
Use the actual product dimensions, package coverage, material density, installed depth, and current local price whenever those values are available. Measure the project in smaller sections when the shape is irregular, and keep fixed costs separate from area-based quantities. For a large purchase, compare the calculator result with the supplier’s own coverage or takeoff before ordering.
Common mistakes to avoid
The most common errors are mixing inches and feet, using nominal dimensions instead of actual product dimensions, forgetting waste or overage, treating volume and weight as interchangeable, and assuming a universal installation depth. Enter the values from your actual product and project specification whenever possible.
Worked planning example
A 20 × 20 ft area at 6 inches deep is 200 cubic feet, or about 7.41 cubic yards before any allowance. Bag counts depend on the actual bag volume.
Useful Topsoil reference values
| Depth | Approx. soil per 100 sq ft |
|---|---|
| 2 in | 0.62 cu yd per 100 sq ft |
| 4 in | 1.23 cu yd per 100 sq ft |
| 6 in | 1.85 cu yd per 100 sq ft |
| 12 in | 3.70 cu yd per 100 sq ft |
Reference values are planning aids. Product specifications and local conditions take precedence.
Frequently asked questions
How many cubic yards of topsoil do I need?
Multiply the project area by the desired depth in feet and divide by 27. Add a reasonable allowance for settling and uneven areas.
How deep should topsoil be?
The appropriate depth depends on whether you are repairing a lawn, establishing a planting bed, filling a raised bed, or changing grade. Follow the project specification.
How many bags are in a cubic yard?
Divide 27 cubic feet by the actual volume of one bag. For example, 1.5-cu-ft bags require 18 bags per cubic yard before rounding for waste.
Can I use this calculator for an irregular project?
Yes, but the best approach is to divide the project into measurable sections and combine the results. Irregular edges, curves, openings, and changes in depth can make a single rectangular measurement less accurate.
What should I verify before buying materials?
Verify the product label or manufacturer coverage, actual dimensions, density or package yield, required installation depth, and supplier delivery terms. For structural or regulated work, also verify the project specification and local requirements.