Garden Guide
How Much Mulch Do I Need?
Mulch is bought by volume, so the two numbers that matter are bed area and mulch depth.
Table of Contents
Quick Formula
For square feet and inches, use: cubic yards = square feet x depth in inches / 324.
For faster planning, enter your area and depth in the Mulch Calculator.
Mulch Coverage Table
| Area | 1 in deep | 2 in deep | 3 in deep | 4 in deep |
|---|---|---|---|---|
| 100 sq ft | 0.31 cu yd | 0.62 cu yd | 0.93 cu yd | 1.23 cu yd |
| 200 sq ft | 0.62 cu yd | 1.23 cu yd | 1.85 cu yd | 2.47 cu yd |
| 300 sq ft | 0.93 cu yd | 1.85 cu yd | 2.78 cu yd | 3.70 cu yd |
| 500 sq ft | 1.54 cu yd | 3.09 cu yd | 4.63 cu yd | 6.17 cu yd |
Choose the Right Depth
Use 2 to 3 inches for most flower beds. Use 1 inch when refreshing an existing layer. Avoid piling mulch against trunks or stems.
- New bare bed: 3 inches.
- Annual refresh: 1 inch.
- Tree ring: 2 to 3 inches, pulled back from bark.
- Weedy path: 3 to 4 inches if the surface is stable.
Example
A 240 square foot bed at 2 inches deep needs 240 x 2 / 324 = 1.48 cubic yards. Round to 1.6 cubic yards if the bed has curves or uneven edges.
FAQ
How Much Mulch Do I Need? FAQ
How many cubic yards of mulch do I need?
Multiply square feet by depth in inches, then divide by 324. That gives cubic yards.
How deep should mulch be?
Two to three inches is enough for most planted beds. A one inch layer is usually enough for refresh work.
How many bags are in one cubic yard of mulch?
One cubic yard is 27 cubic feet. That equals 18 bags at 1.5 cubic feet, 14 bags at 2 cubic feet, or 9 bags at 3 cubic feet.
Should I remove old mulch before adding new mulch?
Remove it if it is matted, moldy, or already too deep. Otherwise, refresh with a thin layer.
Is 4 inches of mulch too much?
It can be too much around plants. Four inches is better for paths or weed suppression, not against stems.
Which calculator helps with mulch bags?
Use the Mulch Calculator and choose your bag size.