Short answer: Multiply length by width in feet to get square feet, multiply by the depth in inches, then divide by 324. That gives cubic yards. One cubic yard covers roughly 100 square feet at 3 inches deep. Our calculator does the math for you, and deliveries have a 3 cubic yard minimum.
Ordering bulk landscape material is easy once you know how much to order. Order too little and you’ll need a second delivery. Order too much and you’re paying for material you don’t need. Here’s how to estimate the right amount for topsoil, mulch, sand, shell, limestone, or fill dirt, in cubic yards.
Understanding the Cubic Yard
Bulk landscape materials are sold by the cubic yard, a measure of volume equal to 27 cubic feet (a cube 3 feet long, 3 feet wide, and 3 feet deep). Because your project probably isn’t shaped like a perfect cube, the trick is converting your space’s length, width, and depth into that same unit.
The Basic Formula
Length (in feet) × Width (in feet) × Depth (in feet), divided by 27, equals the cubic yards you need.
Most people measure depth in inches, not feet, since a few inches of material makes a big difference in coverage. To convert, divide your depth in inches by 12 before multiplying. So the full formula looks like this:
Length (ft) × Width (ft) × (Depth in inches ÷ 12), divided by 27 = cubic yards
Example: Covering a 10-Foot by 20-Foot Bed With 3 Inches of Mulch
- 10 × 20 = 200 square feet
- 3 inches ÷ 12 = 0.25 feet of depth
- 200 × 0.25 = 50 cubic feet
- 50 ÷ 27 = about 1.85 cubic yards
A Faster Rule of Thumb
If you don’t want to do the math by hand, one cubic yard of material covers roughly:
- 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
Typical Depths by Project
These are general starting points. Actual depth depends on your specific project and site conditions:
- New sod or lawn topsoil: 2 to 4 inches
- Garden beds and planting areas: 4 to 6 inches
- Mulch beds: 2 to 3 inches
- Paver base or sand leveling layer: 1 to 2 inches
- Fill dirt for grading or leveling: varies by how much low area needs to be raised
Order a Little Extra
Material settles and compacts after it’s spread, and job sites rarely have perfectly even grades. Adding roughly 5 to 10 percent to your estimate helps you avoid running short partway through the project.
Let Us Do the Math for You
If you’d rather skip the calculations, our Material Calculator lets you enter your project’s length, width, and depth and get an estimated cubic yard amount instantly. You can also call us at (239) 295-8266 and describe your project. We’ll help you figure out how much to order.
Unplugged Designs delivers topsoil, compost, sand, limestone, shell, mulch, and fill dirt by the cubic yard to Fort Myers, Cape Coral, Lehigh Acres, North Fort Myers, Estero, Bonita Springs, Buckingham, and Alva.