Not sure how many bags of mulch to grab? Pick a rectangle bed or a round tree ring, enter its size — or tap a typical bed — and choose how deep you want the mulch. Most beds look and work best at 2–3 inches. The calculator works out the volume, converts it to cubic yards for bulk delivery, and tells you how many bags to buy for the bag size you pick. Have several beds? Add them up one at a time, or type the total area as length × 1. Switch to Metric for meters, centimeters and liter bags.
How it works: area = length × width (or π × radius² for a circle). Volume = area × depth, so 100 sq ft at 3 inches is 100 × 3 ÷ 12 = 25 cubic feet. One cubic yard is 27 cubic feet and covers about 108 sq ft at 3 inches. Bags = volume ÷ bag size, rounded up; most bagged mulch is 2 cu ft (some 1.5 or 3). Bulk mulch is sold by the cubic yard, often in half-yard steps. Metric: m³ = m² × cm ÷ 100, and 1 m³ = 1,000 liters.