Mulch calculator
Reviewed 2026-07-04 · Yards, bags, and the bag-vs-bulk line
One cubic yard of mulch covers 108 sq ft at 3″ deep (162 sq ft at 2″) and equals 13.5 two-cubic-foot bags. Rule: beds total under ~100 sq ft, buy bags; over ~200 sq ft, get bulk delivered, it's usually 30–50% cheaper per yard.
Calculator
Length × width per bed; add the beds together. Circles: radius² × 3.14.
Yards = area × depth(in) ÷ 324. Order whole half-yards for bulk; round bags up. Keep mulch off trunks and siding.
Coverage chart
| Depth | Coverage per yard | Yards per 500 sq ft |
|---|---|---|
| 2″ | 162 sq ft | 3.1 |
| 3″ | 108 sq ft | 4.6 |
| 4″ | 81 sq ft | 6.2 |
Frequently asked
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so 13.5 of the standard 2 cu ft bags, or 9 of the larger 3 cu ft bags. Past about 10 to 12 bags, bulk delivery is usually cheaper per yard, if you have somewhere for the pile.
How deep should mulch be?
Three inches is the standard for weed suppression and moisture. Two inches for refreshing an existing bed. More than 4 inches suffocates roots and invites pests, and never pile it against tree trunks or siding: the "mulch volcano" is how you rot a tree.
How much does a yard of mulch cover?
At 3 inches deep: 108 sq ft. At 2 inches: 162 sq ft. The math is 324 divided by depth in inches.
Bagged or bulk mulch?
Bags win under about 1 yard: cleaner, easy to move, small premium. Bulk wins past 2 yards: often 30 to 50 percent cheaper per yard delivered. In between, whichever your back and driveway prefer.
Related tools
Sources
- Bag sizes and yard math: 27 cu ft per cubic yard; 2 and 3 cu ft standard retail bags.
- Depth guidance per extension service horticulture recommendations (2–4″, never against trunks).