Mulch Calculator
Find out exactly how much mulch to buy for your beds — in cubic yards, bags, or bulk — plus coverage and a quick cost estimate.
What's "mulch"?
A layer of material — usually shredded or chipped wood or bark — spread on top of the soil around plants, trees, or garden beds. It holds in moisture, blocks weeds, and protects roots; it is not soil itself. Need to add or fill in soil instead? Use the Topsoil Calculator.
Length × width bed, border, or row
Estimate only. These figures help you plan how much to buy — they are not engineering or structural advice. Actual needs vary with site conditions, waste, and installation method, so order a little extra and confirm final quantities with your supplier or contractor before you buy or start the job.
Popular bed sizes
Jump to a ready-made answer for a common bed.
How the mulch calculation works
Mulch is sold by volume, so the math is area × depth, then convert to yards or bags.
Rectangle = length × width. Round bed = π × radius² (radius is half the diameter).
Area (sq ft) × depth (ft) = cubic feet. Depth in inches ÷ 12 gives feet. Divide cubic feet by 27 for cubic yards.
Cubic feet ÷ bag size. Bagged mulch is usually 2 cu ft, so a cubic yard ≈ 13.5 bags.
1 cu yd covers ~108 sq ft at 3 inches, ~162 sq ft at 2 inches, ~324 sq ft at 1 inch.
Sources & assumptions
Frequently asked questions
How much mulch do I need for a 200 square foot bed?
At the common 3-inch depth, 200 sq ft needs 200 × 0.25 ft = 50 cubic feet of mulch, or about 1.85 cubic yards — roughly 25 bags of 2 cu ft mulch. At this size, bulk or bags both work; past ~3 cubic yards bulk is usually cheaper.
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet. Bagged mulch is most often 2 cubic feet, so a cubic yard equals about 13.5 bags (27 ÷ 2). For 1.5 cu ft bags it's 18 bags; for 3 cu ft bags it's 9.
How deep should mulch be?
Most landscapes use 2–3 inches of mulch for beds and around 3–4 inches for trees and shrubs. Deeper than 4 inches can hold too much moisture against roots. Keep mulch a couple inches away from trunks and stems.
How much does a cubic yard of mulch cover?
One cubic yard covers about 108 sq ft at 3 inches deep, 162 sq ft at 2 inches, or 324 sq ft at 1 inch. The deeper the layer, the less area a yard covers.
Is bulk or bagged mulch cheaper?
Bulk mulch is usually cheaper per cubic yard once you need more than a few yards, but it requires delivery or hauling. Bagged mulch costs more per volume but is easy to transport and spread for small beds.