How much mulch do I need for a 20×20 bed?
≈ 50 bags (2 cu ft)
That’s about 3.70 cubic yards to cover a 20×20 bed at a 3″ depth.
A 20 ft × 20 ft bed is 400 square feet. At a 3-inch mulch depth (the sweet spot for weed control + moisture), that’s 100.0 cubic feet — about 50 standard 2-cubic-foot bags, or 3.70 cubic yards in bulk.
| Bed area | 400 sq ft |
| Depth | 3 in |
| Volume | 3.70 cu yd (100.0 cu ft) |
| 2-cu-ft bags | 50 bags |
Bulk (by the yard) is usually cheaper above ~10 bags. Refresh 1–2″ yearly rather than re-mulching full depth.
Change the size → open the mulch calculatorGrab the supplies
Don’t forget — your supply list
Everything a job like this needs. Grab it in one trip.
Where do you shop?
As an affiliate, Clearly may earn from qualifying purchases — at no extra cost to you.