Mulch for a 20 × 20 Bed
A 20 × 20 ft bed at 3 inches deep needs about 3.7 cubic yards (≈ 2.83 m³) of mulch — roughly 50 bags of 2 cu ft, covering 400 sq ft.
Adjust the numbers
Pre-filled for a 20 × 20 ft bed — change the size or depth, or switch to metric.
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.
Other bed sizes
Frequently asked questions
How much mulch do I need for a 20x20 bed?
A 20 × 20 ft bed at 3 inches deep needs about 100 cubic feet of mulch — roughly 3.7 cubic yards (≈ 2.83 m³), or about 50 bags of 2 cu ft mulch.
How many bags of mulch for a 20x20 bed?
About 50 bags of 2 cu ft mulch (the most common bag size). Larger 3 cu ft bags would need roughly two-thirds as many.
Should I buy bagged or bulk mulch for a 20x20 bed?
At about 3.7 cubic yards, bulk delivery is usually cheaper than buying 50 bags.