How Much Mulch Do I Need?
Short answer: one cubic yard of mulch covers about 108 square feet at 3 inches deep (162 sq ft at 2″). Multiply your bed’s length by its width, multiply by the depth in inches, and divide by 324 — that’s your cubic yards.
The formula
Square feet × depth in inches ÷ 324 = cubic yards. A bed 10 ft by 20 ft is 200 sq ft; at 3 inches deep that’s 200 × 3 ÷ 324 = 1.85 cubic yards — round up to 2. Use the bulk calculator to do it for you.
Coverage per cubic yard
| Depth | 1 cubic yard covers | Typical use |
|---|---|---|
| 1 inch | 324 sq ft | Top-dressing existing mulch |
| 2 inches | 162 sq ft | Refreshing beds each spring |
| 3 inches | 108 sq ft | New beds, weed control |
| 4 inches | 81 sq ft | Paths and play areas |
How deep should mulch be?
For most beds, 2–3 inches. Less won’t hold back weeds or moisture; more can keep roots too wet. Keep mulch pulled back a few inches from tree trunks and shrub stems — piling it against the bark (a “mulch volcano”) traps moisture and invites rot and pests.
Topsoil and stone
The same formula works for any bulk material. Common depths: 4–6 inches of topsoil for a new bed or lawn area, 2–3 inches of decorative stone over fabric, and about 4 inches of compacted crusher run as a base under a walk or patio. Ask at the counter for your project.
Troy’s bulk mulch prices
| Mulch | Yard, picked up | Half yard |
|---|---|---|
| Black Diamond Mulch | $58 | $34 |
| Dark Mulch | $54 | $34 |
| Red Mulch | $54 | $34 |
| Walnut Mulch | $54 | $34 |
Prices from our register as of October 1, 2026. Pick up at the yard, or have it delivered by dump truck. All bulk materials →