Mulch Calculator
Enter your bed dimensions and desired depth. We'll tell you how much mulch to buy — in volume or bags.
Advanced options
- Area
- 0 sq ft
- Volume
- 0 cu ft
- Cubic yards
- 0
- Bags (2 cu ft)
- 0
- Estimated cost
- —
How the mulch calculator works
We calculate the bed area (length × width for a rectangle, π × radius² for a circle), multiply by your depth, and convert to the selected unit (cubic yards in imperial, cubic meters in metric). For bags, we divide the volume by your bag size.
How deep should the mulch be?
- 2 in / 5 cm — refresh coat on a bed that already has mulch; minimum for aesthetics.
- 3 in / 7.5 cm — the sweet spot for new beds: weed suppression, moisture retention, and it breathes.
- 4 in / 10 cm — maximum for most plants; good for aggressive weed areas.
- Deeper than 4 in / 10 cm — risks suffocating roots and causing "mulch volcano" damage to trees.
Bags vs. bulk
Below about 3 cubic yards (~2.3 m³), bags are usually easier — delivery of bulk mulch typically has a $50–$100 minimum fee. Above that, bulk is noticeably cheaper. A 2 cu ft bag (~57 L) equals 0.074 cubic yards (0.057 m³); it takes ~13.5 bags to make a cubic yard or ~17–20 bags to make a cubic meter.
When to add mulch
Spring (after the ground warms) and fall (before first frost) are both fine. Avoid mulching immediately after heavy rain — you'll trap excess moisture against stems.