Mulch is priced and sold by the cubic yard, but most homeowners and even contractors measure beds in square feet — this calculator converts bed area and depth into cubic yards, compares bulk delivery against bagged pricing, and gives you the total cost for the job before you ever place an order.
3 beds: 18×4 ft, 12×3 ft, 8×3 ft. Depth 3 inches. Bulk delivery at $45/yd³ + $75 delivery.
Single bed 45×4 ft. Depth 3 inches. Bagged 3 cu ft bags at $6.99 each.
5 beds totaling 640 sq ft. Depth 2 inches. Bulk delivery.
Two to three inches is the standard for most garden beds. Two inches suppresses weeds and retains moisture. Three inches is better for hot, dry climates. Avoid going over 4 inches — deep mulch can cause crown rot on perennials and shrubs. Keep mulch 2–3 inches away from plant stems and tree trunks.
One cubic yard equals 27 cubic feet. At 2 cu ft per bag, that's 13–14 bags per yard. At 3 cu ft per bag, about 9 bags. Bulk mulch is almost always cheaper per yard once you account for delivery, but bagged mulch is easier for small areas or tight access.
At 2" depth: 1 yard covers ~160 sq ft. At 3" depth: ~108 sq ft. At 4" depth: ~81 sq ft. This calculator handles any depth and gives you both cubic yards and bag counts.
Dyed wood mulch (black, red, brown) typically lasts 1–2 years before needing refresh. Cedar and cypress mulch breaks down more slowly (2–3 years) and has natural pest-repelling properties. Pine bark nuggets last 2–3 years. Rubber mulch lasts 10+ years but doesn't improve soil.
If the existing mulch layer is less than 2 inches, topping off is fine. If it's already 3+ inches deep, remove and dispose of the old material before adding fresh mulch. Excessive mulch buildup causes root rot and harbors pests.