How to read the coverage chart
Sq ft per cu yd tells you the largest area one cubic yard of mulch can cover at that depth. So 1 cu yd at 3 inches deep covers 108 sq ft. Above 4 inches deep, you won't get more than 81 sq ft per yard — important to know before paying for delivery.
Cu yd per 100 sq ft is the inverse — how much mulch you need to cover a standard 100 sq ft bed at that depth. 0.93 cu yd at 3 inches. Almost exactly one yard.
Bags per 100 sq ft applies the same math to 2 cu ft and 3 cu ft retail bag sizes. Round up — stores don't sell partial bags.
The math behind the chart
One cubic yard equals 27 cubic feet. Coverage equals 27 ÷ (depth in feet). To get depth in feet from inches, divide by 12. So at 3 inches: 27 ÷ 0.25 = 108 sq ft per cu yd. At 6 inches: 27 ÷ 0.5 = 54 sq ft per cu yd. The chart precomputes every depth from 1 to 6 inches so you don't have to.
USDA Forest Service field studies indicate that organic mulch settles by 15–25% in the first season after application, so coverage calculated at installation depth should be paired with a 10% over-order buffer to maintain the target depth through the growing season.
Why this chart beats memorizing one number
“A yard covers 100 sq ft” is the rule of thumb you'll hear at garden centers — and it's only true at 3 inches. Apply at 2 inches and you cover 60% more area per yard. Apply at 4 inches and you cover 25% less. Picking the wrong depth wastes a few bucks on a small project, but on a large property it's the difference between one yard and two.
Print-friendly version
Use the Print button at the top of the chart for a clean black-and-white copy. The page is styled to fit a single sheet of letter paper at 100% zoom. The CSV download opens cleanly in Excel, Google Sheets, or Numbers.