Mulch Depth and Coverage: How Far Does a Cubic Yard Go?
October 21, 2026
A cubic yard is 27 cubic feet, so it covers 324 square feet at a depth of 1 inch (27 ÷ 0.0833), 162 square feet at 2 inches, and 108 square feet at 3 inches. Most garden beds do well with 2 to 3 inches of mulch. A 200 square foot bed at 3 inches deep needs 200 × 0.25 = 50 cubic feet, or about 1.85 cubic yards.
Skip the math and get your answer instantly:
Open the Mulch & Soil Calculator →Coverage Table
Coverage in square feet equals 324 divided by the depth in inches. The same math works for soil, compost, or gravel.
| Depth | Coverage per cubic yard | Typical use |
|---|---|---|
| 1 inch | 324 sq ft | Refreshing existing mulch |
| 2 inches | 162 sq ft | Annual beds, vegetable gardens |
| 3 inches | 108 sq ft | New beds, trees, shrubs |
| 4 inches | 81 sq ft | Heavy weed suppression, paths |
How Deep Should Mulch Be?
Two to three inches suppresses weeds and holds moisture without suffocating roots. Shallow mulch under 2 inches is less effective at blocking weeds, and layers deeper than 4 inches can hold too much moisture and block air to roots.
Keep mulch a few inches away from tree trunks and stems. Piling it against the trunk, the so-called mulch volcano, can cause rot, pests, and girdling roots.
Bags vs. Bulk
Bagged mulch typically comes in 2 cubic foot bags, so 13.5 bags equal 1 cubic yard. For the 200 square foot bed above, 50 cubic feet is 25 bags. Bulk delivery is usually cheaper once you need more than 2 to 3 cubic yards, but there is often a delivery fee and a minimum order.
Mulch settles and decomposes, so order a small amount extra or plan to top up each year. Organic mulches such as shredded bark and wood chips break down over one to three years, while stone lasts longer but does not feed the soil.
Frequently Asked Questions
How many square feet does a yard of mulch cover?
108 square feet at 3 inches deep, 162 at 2 inches, and 324 at 1 inch.
How many bags of mulch are in a cubic yard?
13.5 bags if each bag holds 2 cubic feet.
How deep should mulch be around trees?
About 2 to 4 inches, spread wide and kept several inches away from the trunk.
Does mulch need to be replaced every year?
Organic mulch breaks down and needs topping up every one to two years to keep the depth.