Mulch Calculator
Work out how much mulch your beds need. Enter the length and width of the area, choose a depth, and you get the answer in cubic yards, cubic feet and bags.
Short answer: As a rule of thumb, one cubic yard of mulch covers about 162 sq ft at 2 inches deep, which is roughly 8 bags of 2 cu ft mulch per 100 sq ft.
Fill in the fields above to see your result.
Depth of 2–3 inches is standard for beds. Use 1 inch only for refreshing a bed that is already mulched.
How this mulch calculator works
Every material here comes down to a volume. The area is measured in square feet, the depth is converted from inches to feet, and the result is converted from cubic feet into the unit you actually buy in — cubic yards, tons, or bags.
length (ft) × width (ft) = sq ftsq ft × depth (in) ÷ 12 = cubic feetcubic feet ÷ 27 = cubic yardsBag counts on this page are rounded up to whole bags, because you cannot buy part of a bag. Rounding up also gives you a little spare material, which is what you want on a real job.
Mulch coverage by depth
| Depth | 1 cubic yard covers | 2 cu ft bags per 100 sq ft | 2 cu ft bags per 500 sq ft |
|---|---|---|---|
| 1 inch | 324 sq ft | 5 bags | 21 bags |
| 2 inches | 162 sq ft | 9 bags | 42 bags |
| 3 inches | 108 sq ft | 13 bags | 63 bags |
| 4 inches | 81 sq ft | 17 bags | 84 bags |
A cubic yard is 27 cubic feet, so one yard equals 13.5 bags of 2 cu ft mulch. Bag counts are rounded up.
Frequently asked questions
How much does a cubic yard of mulch cover?
One cubic yard covers about 324 sq ft at 1 inch deep, 162 sq ft at 2 inches, 108 sq ft at 3 inches and 81 sq ft at 4 inches. Most garden beds are mulched at 2 to 3 inches.
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so it takes 13.5 bags of 2 cubic foot mulch to make one cubic yard. In practice, bags are often sold in 2 cu ft or 3 cu ft sizes, so check the bag before you buy.
Is it cheaper to buy mulch in bags or by the yard?
Buying by the cubic yard is almost always cheaper per cubic foot, but it only makes sense if you can take a bulk delivery and have somewhere to put it. Bags are easier for small beds and for carrying through a gate.
How deep should mulch be?
Two to three inches is the usual recommendation. Less than 2 inches does not suppress weeds well, and more than 4 inches can hold too much moisture against stems and harm plants.
How much does a cubic yard of mulch weigh?
It depends on the material and how wet it is. Bark mulch is roughly 600 to 800 lb per cubic yard, while heavier composts can exceed 1,000 lb.
Other calculators
These figures are estimates for planning only. Bag sizes, stone densities and paint coverage vary by product and supplier, so check the label or ask your yard before you order. Last updated 2026-09-30.