Mulch Calculator
Calculate how much mulch you need for any garden bed — in cubic yards, cubic feet and 2 cu ft bags — at the depth your plants actually need.
A 10×10 ft garden bed at 3 in deep needs about 0.93 cubic yards of mulch — roughly 13 bags of 2 cu ft.
How to Use This Mulch Calculator
- Measure the length and width of the bed in feet.
- Choose the mulch depth — 2–3 in is the recommended range for weed control.
- Read the result in cubic yards (for bulk deliveries) and 2 cu ft bags (for store-bought mulch).
The Formula
Mulch volume is area × depth. Convert the depth from inches to feet (3 in = 0.25 ft), multiply by the bed area, and divide by 27 to get cubic yards. One cubic yard covers 108 sq ft at 3 in deep, 162 sq ft at 2 in, and 81 sq ft at 4 in.
V = L × W × DVolume in cubic feet (D in feet)yd³ = ft³ ÷ 27Cubic yards (bulk orders)Bags = ft³ ÷ 22 cu ft bags (rounded up)1 yd³ @ 3 in = 108 ft²Coverage per yard by depthWorked Example: 10×10 Garden Bed
A 10×10 ft bed at 3 in deep: V = 10 × 10 × 0.25 = 25 ft³. That is 25 ÷ 27 = 0.93 cubic yards, or 25 ÷ 2 = 12.5 → 13 bags of 2 cu ft.
How Much One Cubic Yard of Mulch Covers
| Depth | Coverage per cubic yard | 2 cu ft bags per yard |
|---|---|---|
| 2 in | 162 sq ft | 14 bags |
| 3 in | 108 sq ft | 14 bags |
| 4 in | 81 sq ft | 14 bags |
One cubic yard = 27 cu ft = 13.5 bags of 2 cu ft (round up to 14).
How Deep Should Mulch Be?
A 2- to 3-inch layer of mulch provides good weed control for most materials — leaves, pine bark, pine needles, shredded hardwood and wood chips. Deeper is not always better: more than 4 in can smother plant roots and hold too much moisture. This matches the guidance of Clemson Cooperative Extension.
Quick Tips
- Buying by the yard is cheaper for large beds; bags are easier for small projects.
- Replenish organic mulch once a year — it decomposes and feeds the soil.
- Keep mulch a few inches away from tree trunks and house foundations.
Frequently Asked Questions
How many bags of mulch are in a cubic yard?
13.5 bags of 2 cu ft — so 14 bags to be safe (27 cu ft ÷ 2 cu ft per bag).
How much mulch do I need for a 10×10 bed?
At 3 in deep: 25 cu ft = 0.93 cubic yards, or 13 bags of 2 cu ft.
How deep should mulch be?
2 to 3 inches is the recommended depth for weed control and moisture retention.
How many square feet does a yard of mulch cover at 3 inches?
108 square feet (27 cu ft ÷ 0.25 ft depth).