Mulch Calculator
Turn your bed size and mulch depth into cubic yards and a bag count, so you order the right amount the first time.
How Mulch Math Works
Mulch volume is area × depth. Convert depth from inches to feet first (divide by 12), multiply by square footage to get cubic feet, then divide by 27 for cubic yards, which is how bulk mulch is sold.
Worked example: a 10 × 20 ft bed is 200 sq ft. At 3 inches (0.25 ft) that's 200 × 0.25 = 50 cubic feet, or 50 ÷ 27 ≈ 1.85 cubic yards — about 25 bags at 2 cu ft each.
| Depth | 1 cubic yard covers about |
|---|---|
| 1 inch | 324 sq ft |
| 2 inches | 162 sq ft |
| 3 inches | 108 sq ft |
| 4 inches | 81 sq ft |
The full explanation, including irregular beds and when bulk beats bagged, is in How to Calculate Exactly How Much Mulch You Need.