Topsoil Calculator: How To Measure, Estimate, and Order the Right Amount of Soil
If you need to figure out how much topsoil your project requires, you only need three things: measure the area, choose the soil depth, and convert the volume to cubic yards or cubic feet. This calculator does all the calculations for you. It supports multiple areas, different shapes, and all major measuring units to give accurate results without manual math.
Topsoil estimates matter because buying too little slows your project and buying too much increases cost and waste. The guide below explains how topsoil calculation works, recommended depths for common projects, and how soil density affects weight and delivery.
How Topsoil Calculation Works
Most topsoil calculations follow one simple formula:
Volume = Area × Depth
After you calculate volume in cubic feet, convert it to cubic yards by dividing by 27.
Example
- Area: 200 sq ft
- Depth: 0.25 ft (3 inches)
- Volume: 200 × 0.25 = 50 cubic feet
- Cubic yards: 50 ÷ 27 ≈ 1.85 cubic yards
This calculator automates these steps and supports multi-area and multi-unit inputs for more complex projects.
Why Depth Matters
Different projects need different soil depths. Using the right depth improves drainage, root growth, and plant health.
| Project Type | Recommended Topsoil Depth |
|---|---|
| New lawns | 4–6 inches |
| Lawn topdressing | 0.25–0.5 inch |
| Garden beds | 8–12 inches |
| Raised beds | 10–14 inches |
| Flower beds | 6–12 inches |
| Leveling low spots | 1–3 inches |
| Vegetable gardens | 8–12 inches |
Multi-Area Calculation
Many yards have different sections: lawn, garden beds, flower beds, or raised beds. For accurate topsoil estimates, calculate each area separately and then sum the volumes. This calculator allows you to add multiple areas, set their shape, dimensions, and depth, and get a combined total.
Topsoil Weight and Density
Topsoil weight depends on density, which varies with moisture content and composition. Typical topsoil densities:
| Soil Type | Density (kg/m³) |
|---|---|
| Dry Topsoil | 950–1,000 |
| Moist Topsoil | 1,100–1,300 |
| Compost-Heavy Mix | 700–900 |
Knowing density allows you to convert volume into weight, which helps when buying topsoil by the truckload or in bulk bags.
Topsoil Coverage Guide
Here is a quick reference for topsoil coverage per cubic yard based on depth:
| Depth | Square Feet Covered per Cubic Yard |
|---|---|
| 1 inch | 324 sq ft |
| 2 inches | 162 sq ft |
| 3 inches | 108 sq ft |
| 4 inches | 81 sq ft |
| 6 inches | 54 sq ft |
Frequently Asked Questions (FAQ)
How much topsoil do I need for a lawn?
Most lawns require 4–6 inches of topsoil for healthy root growth.
What depth of topsoil is best for a garden bed?
Vegetable and flower gardens typically need 8–12 inches of nutrient-rich soil.
How many bags equal a cubic yard?
If using 40-lb bags, one cubic yard is approximately 54 bags.
Is topsoil heavier when wet?
Yes. Wet topsoil can weigh 30–40% more than dry soil.
How can I measure my yard for topsoil?
Measure length × width in feet or meters, then choose the desired depth. For multi-section yards, calculate each area separately and sum the totals.
