The short answer
Multiply bed length × width in feet, multiply by depth in inches ÷ 12, then divide by 27 for cubic yards. A 2–3 inch layer is right for most beds: 100 sq ft at 3 inches needs about 0.93 cubic yards, or 14 bags of 2 cu ft.
Mulch is cheap per bag and expensive per mistake — too thin and weeds win, too thick and plants rot. Measure once and order the right amount.
Step by step
- Measure each bed's length and width in feet. Split odd shapes into rectangles and circles.
- For a circle around a tree, area = 3.14 × radius × radius.
- Add the areas together for total square feet.
- Choose a depth: 2 inches for fine mulch, 3 inches for bark, 3–4 inches for paths.
- Cubic yards = square feet × (depth ÷ 12) ÷ 27.
- Bags: one cubic yard = 13.5 bags of 2 cu ft. Above about 3 cubic yards, bulk delivery is usually cheaper.
What you need
- Tape measure
- Wheelbarrow
- Garden rake
- Gloves
What it costs
| Item | Typical cost |
|---|---|
| Bagged mulch (2 cu ft) | $3–$7 per bag |
| Bulk mulch (Plus delivery) | $30–$50 per cubic yard |
Common questions
How many bags of mulch in a cubic yard?
13.5 bags of 2 cu ft, or 9 bags of 3 cu ft.
Should I remove old mulch first?
Only if it is matted or more than 3 inches deep. Otherwise fluff it and top up 1 inch.
Does mulch cause termites?
It doesn't attract them, but keep a 6 inch gap between mulch and the house foundation.