📏 Landscape Volume Metrics
Bulk materials like mulch, topsoil, and gravel are sold by the Cubic Yard, which is a measurement of volume (3ft x 3ft x 3ft).
Cubic Yards = (Area x (Depth / 12)) / 27
- The 27 Constant: There are exactly 27 cubic feet in one cubic yard. All bulk suppliers use this divisor for their loading buckets.
- Standard Depth: For weed suppression and moisture retention, a 3-inch depth is the landscape industry standard. 4 inches is used for heavy-duty paths, and 2 inches is used for purely decorative "top-dressing."
- Bagged vs. Bulk: Most mulch bags sold in big-box stores are 2 cubic feet. It takes exactly 13.5 bags to equal one cubic yard. If you need more than 3 cubic yards, it is significantly cheaper to order a bulk delivery.
💡 Expert Tip
Do not pile mulch directly against the trunks of trees (often called "volcano mulching"). This traps moisture against the bark and can cause trunk rot and attract wood-boring insects. Keep mulch at least 3 inches away from the base of the trunk.