Formula
How this estimate works
cubic feet = area x depth in feet; cubic yards = cubic feet / 27
A 300 sq ft bed at 3 in deep with 5% waste needs about 2.92 cubic yards.
Depth drives mulch quantity
Mulch volume changes directly with depth. A 4 inch layer uses twice as much mulch as a 2 inch layer over the same area.
Common mulch depths
Many beds use about 2 to 4 inches depending on plant needs, old mulch depth, weed control goals, and drainage.
Assumptions used
- Bag count uses the selected cubic-foot bag size.
- Coverage per cubic yard changes with depth.
- Bulk and bag costs are estimated separately so you can compare options.
Before you order materials
- Avoid piling mulch against plant stems or tree trunks.
- Check existing mulch depth before adding more.
- Use a consistent finished depth across each bed.
Frequently asked questions
How deep should mulch be?
Many landscape beds use 2 to 4 inches, but avoid piling mulch against trunks or stems.
How much does one cubic yard cover at 3 inches?
One cubic yard covers about 108 square feet at 3 inches deep.
Should I remove old mulch first?
If old mulch is already thick, remove or redistribute it before adding more.