How the mulch math works
Mulch is sold by volume, so the calculator turns your beds into cubic feet and then into the units stores sell.
Cubic feet ÷ 27 = cubic yards
Cubic feet ÷ bag size = bags (rounded up)
Bulk yards are rounded up to the nearest half yard, because most landscape suppliers load in half-yard increments. Ask yours; some sell by the full yard only.
Worked example
A 20 × 10 ft bed is 200 sq ft. At 3 inches deep that’s 200 × 3 ÷ 12 = 50 cubic feet, or 1.85 cubic yards. That’s 25 bags of 2 cu ft, or a 2-yard bulk order.
Picking a depth
| Situation | Typical depth |
|---|---|
| Topping up last year’s mulch | 1–2 in |
| Most flower and shrub beds | 2–3 in |
| New beds or heavy weed pressure | 3–4 in |
Keep mulch pulled back a few inches from tree trunks and plant stems. Mulch piled against bark holds moisture where it can cause rot.
Common questions
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet: 13.5 bags of 2 cu ft, 9 bags of 3 cu ft, or 18 bags of 1.5 cu ft. Round up to whole bags.
How much area does a yard of mulch cover?
About 324 sq ft at 1 inch, 162 sq ft at 2 inches, 108 sq ft at 3 inches and 81 sq ft at 4 inches.
Is bulk mulch cheaper than bags?
Per cubic yard, bulk is usually cheaper, but a delivery fee can cancel the savings on small jobs. Enter your local bag price, bulk price and delivery fee above to see which wins for your beds.
How do I measure an oddly shaped bed?
Split it into rectangles, circles and triangles, then add each as its own area. Small overlaps and gaps roughly cancel out.
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