Mulch Calculator
Calculate how much mulch you need for a garden bed, in cubic yards and standard bags.
Choosing the right mulch depth
Most garden beds benefit from 2-3 inches of mulch — enough to suppress weeds and retain soil moisture without smothering plant roots or trapping excess moisture against stems, which can encourage rot. Going much deeper than 4 inches generally doesn't add benefit and can actually harm plant health.
Depth needs vary somewhat by mulch type — finer mulches like shredded bark settle and compact more than coarser nugget mulch, so finer types are sometimes applied slightly thicker to account for settling over the season.
Bags vs. bulk delivery
For small beds, bagged mulch (typically 2 cubic feet per bag) is convenient and easy to transport. For larger areas, bulk mulch delivered by the cubic yard is usually significantly cheaper per unit volume and reduces plastic bag waste, though it requires a place to dump and spread it from.
As a rough guide, bulk delivery tends to become more cost-effective once a project needs more than about 10-15 bags worth of mulch.
Frequently asked questions
How deep should garden mulch be?
2-3 inches is the generally recommended range for most garden beds — enough to suppress weeds and retain moisture without smothering plant roots or trapping excess moisture against stems.
Is it cheaper to buy mulch in bags or bulk?
For larger areas, bulk mulch delivered by the cubic yard is typically more cost-effective per unit volume than buying many individual bags, though bags are more convenient for small projects.