How this mulch calculator works
Garden bed volume equals area × depth. The area is length × width in square feet, and the depth is converted from inches to feet by dividing by 12. The calculator then converts the volume into bags (using the bag size you enter — most bags are 2 cubic feet) and into cubic yards (divide by 27) for bulk delivery orders.
Two to three inches of mulch is the sweet spot for most beds: enough to suppress weeds and retain moisture, but not so deep that it smothers roots or traps too much moisture against the stem. Add about 10% extra because mulch settles over time, and keep mulch a couple of inches away from tree trunks and plant stems.
Bagged vs bulk
- Bagged mulch: convenient for small beds, about 13-14 bags equal one cubic yard.
- Bulk delivery: cheaper above roughly 3 cubic yards, but comes with a delivery fee.
- Fresh bark mulch darkens as it weathers — color settles within a few weeks.