Mulch Calculator
How many cubic yards or bags of mulch does your garden bed need?
How this is calculated
- Volume in cubic feet = length × width × (depth ÷ 12)
- Cubic yards = cubic feet ÷ 27
- Order amount = cubic yards × (1 + waste % ÷ 100)
- Bags = ⌈order amount × 27 ÷ bag size⌉, using 2 cu ft (standard) and 3 cu ft (bulk) bag sizes.
Common questions
How much mulch do I need for a 10×10 bed at 3 inches?
A 10 ft × 10 ft bed at 3 inches deep needs about 0.93 cubic yards — call it 1 cubic yard once you add the usual 10% for settling. That is roughly 13 of the standard 2 cu ft bags.
How many bags of mulch are in a cubic yard?
One cubic yard equals 27 cubic feet, so it takes about 14 standard 2 cu ft bags or 9 of the larger 3 cu ft bags. Bagged mulch typically costs 2–3 times more per yard than bulk delivery, so above about 3 yards, bulk is almost always the better deal.
How deep should mulch be?
Refresh an existing bed with 2–3 inches. Start a new bed with 3–4 inches to smother weeds. Never pile mulch above 4 inches around plants, and keep it 3–6 inches clear of trunks and stems — "mulch volcanoes" trap moisture and invite rot. Playgrounds using engineered wood fiber need 9–12 inches per CPSC guidance.
How many square feet does one yard of mulch cover?
One cubic yard covers 324 square feet at 1 inch deep, 162 sq ft at 2 inches, 108 sq ft at 3 inches, or 81 sq ft at 4 inches. That is a handy check: multiply your bed area by desired depth in inches, divide by 324, and you get cubic yards directly.
Bags or bulk delivery — which is cheaper?
Bulk wins on volume. At typical prices ($30–$60/yd³ bulk vs $4–$7 per 2 cu ft bag, which works out to $54–$95/yd³), bulk is cheaper from about 1.5–2 yards upward. Bags only make sense for small touch-ups or where wheelbarrow access is impossible.