How much mulch do I need?
Mulch is sold by the cubic yard in bulk or by the cubic foot in bags. The calculator multiplies the bed's length by its width to get square feet, multiplies by the depth in feet, and divides by 27 to get cubic yards.
A quick rule: one cubic yard covers about 324 square feet at 1 inch deep, or 108 square feet at 3 inches.
Example: a 20 × 10 ft bed at 3 inches
- Area: 200 sq ft
- 200 × (3 ÷ 12) = 50 cubic feet
- 50 ÷ 27 = 1.85 cubic yards
- In 2 cu ft bags: 25 bags
How deep should mulch be?
| Use | Typical depth |
|---|---|
| Topping up last year's mulch | 1 in |
| Flower and shrub beds | 2 to 3 in |
| Weed suppression, paths | 3 to 4 in |
Too much mulch can hold water against plant stems and roots. Keep it a few inches away from tree trunks and shrub stems, and don't pile it into a cone around trees.
Bags or bulk?
- Bags are handy for small beds and easy to carry.
- Past about 2 cubic yards, bulk delivery is usually less work. That's roughly 27 bags of 2 cubic feet per yard.
- Bulk mulch can settle, so order a little extra if you're filling a large area.
Laying gravel or river rock instead? Use the gravel calculator.
Frequently asked questions
How much area does a yard of mulch cover?
About 324 square feet at 1 inch deep, 162 square feet at 2 inches and 108 square feet at 3 inches.
How many bags of mulch are in a yard?
About 13.5 bags of 2 cubic feet, or 9 bags of 3 cubic feet. A cubic yard is 27 cubic feet.
How deep should mulch be?
Two to three inches is typical for beds. Use about one inch to freshen up existing mulch.
How many bags of mulch do I need for a 10x10 area?
At 3 inches deep, 100 square feet needs 25 cubic feet, which is 13 bags of 2 cubic feet.
Sources
Results are estimates for planning. Product coverage, site conditions and installation methods vary, so check manufacturer guidance before you buy.