ONE-CUBIC-YARD ANSWER
How Much Does a Yard of Mulch Cover?
One cubic yard of mulch covers 324 sq ft at 1 inch deep, 162 sq ft at 2 inches, 108 sq ft at 3 inches, or 81 sq ft at 4 inches. A cubic yard is 27 cubic feet; changing the depth changes the area it can cover.
108 SQ FT WITH ONE YARD
Your layer will be 3 inches deep
One cubic yard provides 27 cubic feet. Spread over 108 sq ft, that is 3 inches deep.
One-yard coverage by depth
| Depth | Area covered by 1 cubic yard | Example rectangle |
|---|---|---|
| 1 inch | 324 sq ft | 18 ft × 18 ft |
| 2 inches | 162 sq ft | 9 ft × 18 ft |
| 3 inches | 108 sq ft | 9 ft × 12 ft |
| 4 inches | 81 sq ft | 9 ft × 9 ft |
| 5 inches | 64.8 sq ft | 6 ft × 10.8 ft |
| 6 inches | 54 sq ft | 6 ft × 9 ft |
The fast formula
One cubic yard is 27 cubic feet. At a chosen depth in inches, its coverage is 324 ÷ depth in inches square feet. The 324 comes from 27 cubic feet × 12 inches per foot.
The 100-square-foot trap
A 10 ft × 10 ft bed is 100 sq ft, not 108 sq ft. One yard over that bed makes a layer 3.24 inches deep, not exactly 3 inches. “About 100 sq ft at 3 inches” is a useful approximation, but use your actual measured area when ordering.
Use the reverse check before delivery
Most mulch calculators start with your bed and tell you how many yards to order. This page starts with one yard and tells you what depth it will make over the area you measured. Use it to check a supplier quote, a delivery quantity, or whether a rounded yard amount will meet your intended depth.
Common coverage mistakes
- Using 324 sq ft for every depth. It is only the one-inch coverage figure.
- Calling every 10 ft × 10 ft bed “one yard at 3 inches.” The exact 3-inch area is 108 sq ft.
- Measuring a curved bed as its outside rectangle without subtracting unmulched space.
- Adding all beds after rounding each one separately. Add their areas or volumes first, then round the final order amount.
FAQ
How many bags equal one yard of mulch?
One cubic yard is 27 cubic feet. It equals 13.5 2 cu ft bags, so 14 whole bags provide at least one cubic yard. For a bag-by-bag calculation, use How Many Bags of Mulch Do I Need?.
How many yards do I need for 100 sq ft at 3 inches?
100 × 3 ÷ 324 = 0.93 cubic yards. This is the same as 25 cubic feet ÷ 27. Whether to round an order is a purchasing decision; the formula itself does not add extra material.
Can I use the main calculator for a circle?
Yes. The Mulch Calculator estimates rectangular and circular beds, then returns cubic yards, cubic feet, and common bag counts.
Related reading: Mulch Coverage Calculator — calculate net coverage after subtracting an unmulched circle, then reverse-check the yardage.