How Much Mulch Do I Need?
Multiply your bed's area in square feet by your depth in feet (3 inches is 3", or 0.25 ft), then divide by 27 for cubic yards, or by 2for standard bags. That's the math for one bed at the standard depth; for several beds at once, a different depth, or a direct bag-count output, the mulch calculator does it for you. This page is a quick reference table by bed size, plus how to convert between a bulk cubic-yard quote and a bag count.
Cubic yards and bags by bed size
Figures below are at the standard 3-inch depth, recommended by Clemson Cooperative Extension, "Mulch", with bag counts rounded up to the next whole 2 cu ft bag.
| Bed area | Bulk (cubic yards) | Bags |
|---|---|---|
| 50 sq ft | 0.47 cu yd | 7 bags |
| 100 sq ft | 0.93 cu yd | 13 bags |
| 200 sq ft | 1.86 cu yd | 25 bags |
| 300 sq ft | 2.78 cu yd | 38 bags |
| 500 sq ft | 4.63 cu yd | 63 bags |
For beds shallower or deeper than 3 inches — extension guidance allows 2 to 4 inches for most garden beds — scale these figures up or down proportionally, or use the calculator to enter your exact depth directly.
Converting between a bulk quote and a bag count
Landscapers and delivery suppliers quote bulk mulch in cubic yards, but a lot of people shopping for a smaller job think in bags — converting between the two is simple arithmetic once you know the 2 cu ft standard bag size and the 27cu ft in a cubic yard. If a landscaper quotes 3 cubic yards for your beds and you'd rather buy bagged mulch yourself: 3 cu yd × 27 = 81 cubic feet, and 81 ÷ 2 = 40.5, rounded up to 41 bags. Going the other direction — say you have 60 bags left over from last year and want to know how much that is for planning a bulk top-up order: 60 × 2 = 120 cubic feet, and 120 ÷ 27≈ 4.45 cubic yards. Most bulk suppliers sell in half- or quarter-yard increments, so that would round to a 4.5 cubic yard order once you confirm your specific supplier's minimum increment.