Mulch Calculator
Calculate how much mulch you need in cubic yards, bags, and estimated cost.
Bed Shape
Dimensions
Your Results
Enter your bed dimensions above to see results
Common Bed Sizes Reference
| Bed Size | 3" Depth (cu yd) | 4" Depth (cu yd) |
|---|---|---|
| 4×10 ft | 0.37 | 0.49 |
| 6×20 ft | 1.11 | 1.48 |
| 8×15 ft | 1.11 | 1.48 |
| 10×20 ft | 1.85 | 2.47 |
| 10×30 ft | 2.78 | 3.7 |
| 12×40 ft | 4.44 | 5.93 |
*Based on rectangular beds.
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Try YARDGEN – It’s FreeWhy Mulch Matters for Your Landscape
- Moisture and temperature: A suitable mulch layer can help retain soil moisture and moderate temperature swings.
- Weed suppression: Mulch can reduce weed emergence. Keep it away from trunks and stems, and avoid burying plants.
- Material choice: Bark, wood chips, straw, and mineral mulches differ in appearance, weight, longevity, and suitability.
- How the volume works: For measurements in feet and depth in inches: area × depth ÷ 324 = cubic yards. The metric switch changes bed dimensions to meters; depth remains inches as labeled.
Formula reference: Iowa State University Extension.
Frequently Asked Questions
How deep should mulch be?
Choose a depth suited to your plants, material, existing mulch, and drainage. The 3-inch starting value is an estimate input, not a universal planting instruction.
How many bags of mulch are in a cubic yard?
One cubic yard is 27 cubic feet, or 13.5 bags of 2 cubic feet. Round up the bag count when ordering and check the size on the bag.
When is the best time to mulch?
Mulch when it suits your local climate and planting schedule. Check soil moisture and existing coverage before adding a new layer.
Should I remove old mulch before adding new?
Measure the existing layer first. Avoid repeatedly adding a full new depth where enough mulch remains.
Bulk mulch vs. bagged: which is better?
Compare the actual volume, material, delivery charge, access, and handling effort. Edit the bulk price in Bonus Calculations to compare against the illustrative $5 per 2 cu ft bag.