Measure your beds, pick a depth and get cubic yards for bulk mulch or the number of bags.
How far 1 cubic yard and one bag of mulch go at common depths. It’s the cubic-yard formula worked backward.
| Depth | 1 cubic yard covers | One 2 cu ft bag covers | One 3 cu ft bag covers |
|---|---|---|---|
| 1 in | 324 sq ft | 24 sq ft | 36 sq ft |
| 2 in | 162 sq ft | 12 sq ft | 18 sq ft |
| 3 in | 108 sq ft | 8 sq ft | 12 sq ft |
| 4 in | 81 sq ft | 6 sq ft | 9 sq ft |
Divide 324 by the depth in inches. At 2 inches a cubic yard covers about 162 sq ft, at 3 inches about 108 sq ft and at 4 inches about 81 sq ft. That’s Texas A&M AgriLife Extension’s cubic-yard formula worked backward.
A cubic yard is 27 cubic feet, so it takes 13.5 bags of 2 cubic feet (Texas A&M’s table rounds that to 14) or 9 bags of 3 cubic feet. Iowa State Extension says bagged mulch is most often sold in those two sizes.
Mississippi State University Extension recommends 1 to 2 inches for annual bedding plants, 2 to 3 inches for shrubs and roses, and 3 to 4 inches for trees, and warns against piling mulch up against tree trunks.
Yes. Texas A&M suggests rounding up to the nearest whole or half yard, depending on how your supplier sells it. The calculator shows that rounded figure under the cubic yards.
Measure across the widest point of a round bed and enter it as a circle; the calculator uses 3.14 × radius × radius. Split curved or L-shaped beds into rectangles and circles and add each one as its own area.
UF/IFAS Extension says to keep mulch about 1 foot from the base of trees and large plants, and to leave a couple of inches bare around smaller plants. Mulch piled against a trunk holds moisture, which can lead to trunk rot. Around a tree, it recommends a mulched circle at least 8 feet across, ideally out to the drip line.
Yes. UF/IFAS recommends 3 inches and says not to go deeper, because too much mulch can divert rain and irrigation meant for plant roots. Seedlings, small vegetables and herbs need only about 1 inch.
UF/IFAS says to top it up when the layer falls below 2 inches. Add a thin new layer over the old one rather than replacing the whole bed, and lightly rake older mulch that has matted down.
Free to cite or embed. The embed shows the full calculator, with a link back to this page.
Results are estimates. Suppliers’ bag sizes, pallet sizes and stone weights vary, so check theirs before you order.
Landscape fabric is worth it under rock and gravel, where it keeps stones from sinking into the soil. In permanent beds under bark or wood chips, many extension experts say skip it: weeds root on top, plant roots grow into it and it's hard to remove.
September 21, 2026
Multiply your bed's square footage by the depth in inches, then divide by 324 to get cubic yards. At a typical 2 to 3 inches, 1 cubic yard covers about 108 to 162 square feet, or about 13.5 bags of 2 cubic feet each.
September 8, 2026
