Formula
How this estimate works
cubic feet = area x depth in feet; cubic yards = cubic feet / 27
A 200 sq ft bed at 3 in deep needs about 1.85 cubic yards before waste.
How to calculate mulch
Multiply area by depth to get cubic feet. Depth must be converted from inches to feet. Divide cubic feet by 27 for cubic yards, or divide by bag size for bag count.
Common mulch depth
Many garden beds use 2 to 4 inches of mulch. At 3 inches deep, one cubic yard covers 108 square feet before waste or rounding.
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
- Use 2 to 4 inches for many landscape beds unless plant needs differ.
- Remove old excess mulch before adding a thick new layer.
- Round up for curved beds and irregular edges.
Frequently asked questions
How many bags are in a cubic yard?
For 2 cubic foot bags, one cubic yard is about 14 bags because 27 cubic feet equals one cubic yard.
Should I buy bags or bulk mulch?
Bags are convenient for small areas. Bulk mulch is often more economical for larger beds if delivery is available.
Can I use this for compost or bark?
Yes for rough volume planning, but material density and coverage can vary.