How Much Mulch Do I Need?
How much mulch you need is your bed area times the depth, in cubic yards or bags. At a 3 inch depth, a 100 square foot bed needs about 0.93 cubic yards, or roughly 13 of the 2-cubic-foot bags. The table below covers common bed sizes, and the calculator works out your exact amount from your area and depth.
| Bed area | Cubic yards | 2 cu ft bags |
|---|---|---|
| 50 sq ft | 0.46 | 7 |
| 100 sq ft | 0.93 | 13 |
| 200 sq ft | 1.85 | 25 |
| 300 sq ft | 2.78 | 38 |
| 500 sq ft | 4.63 | 63 |
| 1000 sq ft | 9.26 | 125 |
Get your exact number
Calculate your exact amount with the mulch calculatorHow Do You Calculate Mulch Needed?
To calculate mulch, multiply the bed area by the depth in feet, then divide by 27 for cubic yards. A 200 square foot bed at 3 inches (0.25 feet) deep is 50 cubic feet, or 1.85 cubic yards. Mulch comes in 2-cubic-foot bags, and there are about 13.5 bags in a cubic yard. For beds over a few hundred square feet, bulk delivery by the yard beats buying many bags. The calculator gives both.
How Deep Should Mulch Be?
Mulch should be 2 to 3 inches deep for most beds: deep enough to suppress weeds and hold moisture, but not so deep it smothers roots. Use 3 inches for new beds and weed control, 2 inches for topping up existing mulch. Going deeper than 3 inches wastes material and can harm plants. The table uses 3 inches; the calculator lets you set any depth for your beds.
Related answers
Frequently asked questions
- How much mulch do I need for 100 square feet?
- At 3 inches deep, 100 square feet needs about 0.93 cubic yards, or roughly 13 of the 2-cubic-foot bags.
- How many bags of mulch are in a yard?
- About 13.5 of the 2-cubic-foot bags make one cubic yard of mulch.
- How deep should mulch be?
- 2 to 3 inches for most beds. Use 3 inches for new beds and weed control, 2 inches for topping up.