Cubic yards & bags of mulch from area and depth
Enter your bed dimensions (or a known square footage) and target depth. The calculator returns cubic yards for bulk delivery, the number of 2 cubic-foot bags if you're buying retail, and both costs so you can see how much bulk saves. One cubic yard of mulch covers about 324 sq ft at 1 inch deep, 162 sq ft at 2 inches, or 108 sq ft at 3 inches.
A 20 ft × 10 ft bed (200 sq ft) mulched 3 inches deep: 200 × 3 ÷ 12 = 50 ft³ = 1.85 cubic yards (order 2). In bags: 50 ÷ 2 = 25 bags. Bulk at $40/yd³ ≈ $80 delivered vs $112 in bags — bulk wins on any bed over about 1 yard.
How deep should mulch be? 2–3 inches for established beds, 3–4 inches for new beds or weed suppression. Avoid piling more than 4 inches — roots suffocate, and never mound mulch against tree trunks ("mulch volcanoes" cause rot).
How many bags of mulch equal a yard? 13.5 two-cubic-foot bags make one cubic yard. Nine 3-cubic-foot bags also make a yard.
How much does a yard of mulch weigh? Mulch weighs 400–800 lb per cubic yard depending on moisture — a half-ton pickup safely hauls about 2–3 yards of dry mulch.
How do I mulch around trees? Cover the root zone out to the drip line if possible, keep mulch 3–6 inches back from the trunk, and maintain a flat, even 3 inch layer.