A 20 ft × 10 ft bed at 3 inches deep needs about 1.85 cubic yards of mulch — roughly 25 standard 2-cubic-foot bags. Past that scale, bulk delivery by the cubic yard is usually the cheaper option.
How many bags of mulch do I need
Enter your bed's length and width and your target depth, and this calculator converts straight to bag count using your bag size (2 cubic feet is the common standard, but adjustable if yours differs).
Mulch calculator cubic yards, for bulk pricing
The same result shown in cubic yards and cubic feet lets you compare against bulk delivery pricing, which almost always quotes by the cubic yard rather than by the bag.
Mulch depth calculator, not too shallow or too deep
2-3 inches is typical for topping up an existing bed; 3-4 inches for a brand new one. Piling mulch much deeper than that doesn't help — it can actually suffocate plant roots instead of protecting them.
