Mulch Calculator: How Much Mulch Do I Need?
Enter your bed size and depth for an instant estimate in cubic yards for bulk delivery and the number of bags to buy. Works for wood, bark, and rubber mulch — no sign-up, no guesswork.
Mulch Calculator
Enter your bed size and how deep you want the mulch. The calculator gives you cubic yards for bulk delivery and the number of bags to buy.
How to use this mulch calculator
Measure your bed's length and width in feet and choose a depth (3 inches is the usual default). Pick your bag size — most bagged mulch is 2 cubic feet — and add any other beds under Advanced. The calculator returns both cubic yards (for bulk) and a bag count.
How deep should you spread mulch?
2–3 inches maintains an established bed and conserves moisture. 3–4 inches suits new beds and better weed control. Resist going deeper: excessive mulch starves roots of oxygen and wastes money, and piling it against trunks ("volcano mulching") invites rot and pests. Pull mulch back a few inches from stems.
Bags vs. bulk delivery
Bags are easy to handle, store, and price for a single bed. But they add up: a cubic yard is about 14 of the standard 2 cubic foot bags. Once you need more than about two cubic yards, bulk delivery is usually far cheaper per yard and saves you opening and hauling dozens of bags. The calculator shows both numbers so the choice is easy.
How much area does a yard cover?
One cubic yard of mulch covers roughly 108 square feet at 3 inches deep, or about 162 square feet at 2 inches. That relationship is handy for a sanity check: if you know your total bed area, divide by the coverage at your chosen depth to cross-check the calculator.
Frequently asked questions
How much mulch do I need for a 10×10 bed?
A 10 ft × 10 ft bed (100 sq ft) at 3 inches deep needs about 25 cubic feet of mulch, which is roughly 0.9 cubic yards — or about 13 of the standard 2 cubic foot bags.
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet. With the common 2 cubic foot bags, that is about 13.5 bags per cubic yard (round up to 14). With 3 cubic foot bags it is about 9 bags. The calculator gives you the exact count for your beds.
How deep should mulch be?
Two to three inches is right for maintaining established beds. Go three to four inches for new beds or stronger weed suppression. More than about four inches can suffocate roots and waste material, and mulch should never be piled against plant stems or tree trunks.
Is it cheaper to buy mulch in bags or bulk?
For a small bed, bags are convenient and competitively priced. Once you pass roughly two cubic yards, bulk delivery is usually significantly cheaper per yard and means far less to lift and open. The calculator shows both so you can compare.
How much area does a yard of mulch cover?
One cubic yard covers about 108 square feet at 3 inches deep, or about 162 square feet at 2 inches. Spread thinner and it covers more area but suppresses fewer weeds; spread thicker and you cover less.
Should I subtract for plants in the bed?
Generally no — plants take up little volume at mulch depth, and a small surplus is useful for touch-ups. For very densely planted beds you can shave 5–10% off, but most people leave the estimate as is.
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