Mulch Calculator

1. Choose your input method. If you have a simple rectangular bed, enter the length and width in feet. For irregularly shaped areas or if you already know your square footage, switch to direct area input and type the total square feet.
2. Enter the desired depth. Use the preset buttons for 1, 2, 3, or 4 inches, or type a custom depth. For most planting beds, 2 to 3 inches is the standard recommendation. Use 3 inches if you want strong weed suppression. Do not exceed 4 inches since deep mulch can cause root suffocation and create habitat for pests and rot.
3. Read cubic yards for bulk delivery. Landscaping suppliers sell mulch by the cubic yard. One cubic yard covers 324 square feet at 1 inch deep, 162 ft² at 2 inches, 108 ft² at 3 inches, or 81 ft² at 4 inches. Minimum delivery is usually 1 to 2 yards.
4. Use the bag count for small projects. Bagged mulch is sold in 2 cubic foot bags at most home improvement stores. This is more expensive per cubic yard than bulk but is convenient for small beds or tight access areas where a dump truck cannot reach.

Example: a 20 ft x 10 ft garden bed at 3 inches deep needs 50 cubic feet, or 1.85 cubic yards. If buying bags, that is 25 two-cubic-foot bags.

Mulch is measured in cubic units because it fills three-dimensional space. The formula converts area and depth into cubic feet, then into cubic yards for bulk ordering.

When comparing bulk vs. bag pricing: a cubic yard of mulch typically costs $25 to $45 for bulk delivery. Bagged mulch at 2 cubic feet per bag runs about $4 to $7 per bag, which works out to $54 to $95 per cubic yard. Bulk is significantly cheaper for any project over 3 to 4 cubic yards, though delivery minimums and driveway access matter. Many suppliers offer free delivery above a minimum order of 2 to 3 yards.