Topsoil Calculator
Installing a new lawn, leveling yard low spots, or preparing raised garden beds? Our free Topsoil Calculator computes exact topsoil volume in cubic yards, cubic feet, or cubic meters. Factoring in area dimensions, topsoil depth, compaction settling, and bulk density, you will know precisely whether to buy retail bags or order bulk truckload delivery.
Project Inputs
Enter your measurements to calculate exact materials
Enter measurements above to view calculation results.
Step-by-Step Calculation Example
Scenario: Preparing a 30 ft by 20 ft lawn area (600 sq ft) with a 4-inch layer of screened topsoil and a 10% compaction settling buffer.
Calculate Surface Area: 30 ft × 20 ft = 600 sq ft.
Convert Depth to Feet: 4 inches ÷ 12 = 0.333 ft.
Compute Net Volume: 600 sq ft × 0.333 ft = 200 cubic feet.
Add 10% Compaction & Settling Buffer: 200 cu ft × 1.10 = 220 cubic feet.
Convert to Cubic Yards: 220 cu ft ÷ 27 = 8.15 cubic yards.
Calculate Estimated Weight: 220 cu ft × 75 lb/cu ft = 16,500 lbs (8.25 Tons).
Determine Retail Bag Equivalents: 220 cu ft ÷ 0.75 cu ft per bag = 294 bags (0.75 cu ft size) or 110 bags (2.0 cu ft size).
Topsoil Volume & Compaction Formula
Volume = Surface Area × Depth × (1 + Settling Buffer %) Surface area is calculated according to the selected geometry (Length × Width for rectangular lawns, π × Radius² for circular zones, or 0.5 × Base × Height for triangular sections). Multiplying area by topsoil depth yields the uncompacted geometric volume. A settling buffer (default 10%) is added because loose topsoil settles significantly after leveling and rainfall.
Formula Variables
Calculation Assumptions
- Standard blended topsoil weighs approximately 75 to 80 lb per cubic foot (1.20 to 1.28 tonnes per cubic meter).
- One cubic yard equals 27 cubic feet.
- One cubic yard provides 324 square feet of coverage at a 1-inch depth (or 81 sq ft at 4 inches).
- Standard retail topsoil bags contain 0.75 cu ft (40 lb bags), 1.0 cu ft, or 2.0 cu ft.
- Freshly spread topsoil settles by 8% to 15% after watering, rolling, or sod installation.
Frequently Asked Questions
Common homeowner and DIY questionsTopsoil Calculator
How much topsoil do I need?
To calculate topsoil, multiply the area length (ft) by width (ft) by depth (ft), then divide by 27 to get cubic yards. For example, a 20x20 ft lawn (400 sq ft) with a 3-inch depth requires 100 cubic feet (3.70 cubic yards). Adding a 10% settling buffer brings the total to approximately 4.07 cubic yards.
How deep should topsoil be for a new lawn or sod?
For new lawns seeded from scratch or laying sod, a minimum of 4 to 6 inches of rich topsoil is recommended to establish strong root systems. For overseeding or top-dressing existing lawns, a light 1/4 to 1/2 inch layer is ideal.
How much area does one cubic yard of topsoil cover?
One cubic yard of topsoil covers 324 square feet at 1 inch deep, 162 square feet at 2 inches deep, 108 square feet at 3 inches deep, 81 square feet at 4 inches deep, and 54 square feet at 6 inches deep.
How many bags of topsoil equal one cubic yard?
One cubic yard equals 27 cubic feet. That equals 36 bags of 0.75-cu-ft topsoil (common 40-lb bag size), 27 bags of 1.0-cu-ft topsoil, or 13.5 (14 rounded up) bags of 2.0-cu-ft topsoil.
What is the difference between topsoil and garden soil?
Topsoil is natural screened soil rich in minerals, ideal for grading, lawn establishment, and filling large depressions. Garden soil is topsoil specially blended with organic compost, peat, and nutrients formulated for vegetables and flowers.
Should I order extra topsoil for settling and compaction?
Yes, always add 10% to 15% extra topsoil. Loose uncompacted topsoil contains air voids and shrinks significantly when watered, rolled, or walked on during sod installation.
Is it cheaper to buy bagged topsoil or bulk truckload delivery?
For projects requiring more than 1.5 to 2 cubic yards (over 50 bags of 0.75 cu ft), bulk delivery from a local landscape supplier is generally 40% to 60% cheaper than buying individual bags at a home improvement store.
Related Tools inLandscaping & Garden
Explore connected calculators for your home project
Concrete Calculator
Calculate concrete volume in cubic yards or cubic meters and estimate 40lb, 60lb, and 80lb pre-mix bag counts for slabs, footings, and columns.
Gravel Calculator
Calculate gravel and crushed stone requirements in cubic yards, metric tonnes, tons, and 50lb bags for driveways and paths.
Mulch Calculator
Calculate mulch volume in cubic yards or cubic meters and find bag counts for 2 cu ft, 3 cu ft, and 50L garden bags.
Room Area Calculator
Calculate square footage, square meters, perimeter, and diagonal corner dimensions for rooms and project planning.
Soil Calculator
Calculate the exact amount of soil needed in cubic yards, cubic feet, cubic meters, weight, and store bags for garden and raised beds.