Mulch coverage and depth guide
Depth determines quantity: doubling depth doubles the theoretical volume.
Reviewed August 2026 · HomeCostPilot Editorial Team
Convert area to cubic yards
Multiply bed length by width to find square feet. Multiply by depth in feet, then divide by 27. At three inches deep, one cubic yard theoretically covers about 108 square feet; at two inches, about 162 square feet.
Choose depth for the bed
An established bed may need only a refresh, while a new installation may need more material. University of Minnesota Extension recommends a two-to-four-inch range as general landscape guidance, while plant type, existing mulch and site moisture still matter.
Measure irregular areas
Break curves into rectangles and triangles, then subtract substantial patios, rocks and dense plant masses. Add a modest ordering allowance for settlement and uneven grade rather than rounding every dimension upward.
Placement cautions
- Keep mulch away from trunks and plant stems.
- Do not bury drainage openings or siding clearances.
- Account for delivery location and wheelbarrow access.
- Specify whether old mulch, weeds and edging are included.