Every landscaping material — mulch, topsoil, stone, wood chips — is priced and delivered by the cubic yard. But most homeowners think in square feet: "my garden bed is about 10 by 20 feet." Bridging that gap requires one extra step, and it's simpler than it sounds.
The Universal Formula
The formula for any rectangular area is: (Length × Width × Depth) ÷ 27 = Cubic Yards. The division by 27 converts cubic feet to cubic yards (since 1 cubic yard = 27 cubic feet). All measurements must be in feet — so convert inches to feet by dividing by 12 before calculating.
Example: A garden bed 15 feet long, 4 feet wide, and 3 inches (0.25 feet) deep needs: 15 × 4 × 0.25 ÷ 27 = 0.56 cubic yards. Round up to 0.6 or order a full yard if you have other small areas to cover.
Circular Areas (Tree Rings, Round Beds)
For circular areas, use: (π × Radius² × Depth) ÷ 27. The radius is half the diameter. For a tree ring 8 feet in diameter (4-foot radius) at 3 inches deep: 3.14159 × 16 × 0.25 ÷ 27 = 0.47 cubic yards.
Triangular Areas
For triangular beds: (0.5 × Base × Height × Depth) ÷ 27. A triangular corner bed with a 10-foot base, 8-foot height, and 3-inch depth: 0.5 × 10 × 8 × 0.25 ÷ 27 = 0.37 cubic yards.
Quick Reference: Coverage per Cubic Yard
| Depth | Coverage 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 |
Always Add a Buffer
Material compresses after delivery, and it's easy to underestimate irregular edges and corners. Add 10% to your calculated total for mulch and topsoil, and 15% for stone (which has more variation in how it settles). It's always cheaper to order slightly more in one delivery than to pay a second delivery fee.
Use Our Built-In Calculator
Rather than doing the math yourself, use the Yard Calculator built into our quote form and each product page. Enter your shape, dimensions, and depth and it calculates cubic yards and estimated cost automatically. We deliver mulch, topsoil, stone, and wood chips throughout Washington, Warren, and Saratoga Counties — typically within the same week.
