Mulch & Soil
Bed size and depth become cubic yards — and the bag count that decides between the trunk and a bulk drop.
Your buy list
0
bags · or 0 cubic yards bulk- Bed area
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- Volume needed
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- Bulk verdict
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Keep mulch a hand-width off trunks and stems.
How the yard math works
A cubic yard is a 3×3×3-foot box — 27 cubic feet. Your bed's footprint times depth in feet gives cubic feet; divide by 27 for yards. Stores sell that same volume in compressed bags, so the bag count is just your volume over the bag size, always rounded up because partial bags don't stack.
The crossover matters more than the math: around fifteen 2-cubic-foot bags you're carrying a cubic yard by hand, and past twenty bags a landscape supplier's minimum drop beats both the price and the driveway trips.
Depth discipline
Three inches suppresses weeds and holds moisture. Piling deeper than four inches starves roots of air and grows artillery fungus on house siding — if last year's mulch is still healthy, top-dress at half the calculated depth instead.
On the counter
The assumptions this calculator ships with — every one is adjustable in the form.
- Bag size
- 2 cu ft standard; switch the selector for 3 cu ft bags
- Depth
- 3 inches default — the weed-suppressing sweet spot
- Rounding
- Bag counts always round up to the whole bag
Questions from the aisle
How much does a yard of mulch cover?
One cubic yard covers about 160 square feet at 2 inches deep, or 108 square feet at 3 inches — the recommended depth for weed suppression.
Bags or bulk delivery?
Under about 15 bags (a cubic yard or so), grab bags off the pallet. Past 20 bags, bulk delivery by the yard is cheaper and spares your back — the bag line above tells you exactly where you sit.
How deep should mulch be?
2–3 inches for beds; keep it a hand-width off trunks and stems. Deeper than 4 inches suffocates roots and invites fungus — more is not better.
Does topsoil use the same math?
Yes — volume is volume. For topsoil use 4–6 inches depth for new beds and note it weighs more per yard than bark mulch when ordering delivery.