Mulch Calculator for Cubic Yards
Estimate how many cubic yards of mulch you need from the area of your bed and planned depth in inches.
Build the Estimate
Measurement controls, project presets, and a material result card for this calculator.
Formula and Assumptions
Cubic feet = area square feet x depth inches / 12. Cubic yards = cubic feet / 27.
- Mulch settles after installation.
- Most refresh projects use less depth than new beds.
Worked Example
- 420 sq ft of beds
- 3 inch mulch depth
- 27 cubic feet per cubic yard
- bulk delivery order
A 3 inch depth is 0.25 ft, so 420 sq ft needs 105 cubic feet of mulch. Dividing by 27 converts that to cubic yards.
The beds need about 3.9 cubic yards, so a 4 cubic yard bulk order is a practical starting point.
Measurement Tips
- Measure bed length and width in feet or estimate irregular beds as rectangles and triangles.
- Use a smaller depth for refresh jobs where old mulch remains.
- Keep mulch below siding and tree trunks after spreading.
Buying Notes
- Bulk yards are usually better for larger beds than many small bags.
- Order a little extra when beds have uneven soil or heavy edging.
Common Mistakes
- Entering depth in feet when the calculator expects inches.
- Forgetting that fluffy mulch settles after watering and foot traffic.
Frequently Asked Questions
Is this mulch calculator cubic yards exact?
No. It is an estimate based on common project formulas and the assumptions shown on the page. Always confirm package labels and local conditions before buying materials.
Should I add extra material?
Most projects need extra material for cuts, waste, damaged pieces, uneven surfaces, or future repairs. The calculator includes a waste factor where it matters.
Can I print the result?
Yes. Use the print action on the page to keep a simple copy of the inputs, formula, and estimated material list.