Measure the actual bed, choose a target finished depth, and enter the bag size printed on the product if buying packaged mulch.
01 / Formula
How this is calculated
Cubic yards = area sq ft × (depth in ÷ 12) ÷ 2702 / Assumptions
What the estimate assumes
- ✓Depth is uniform across the bed.
- ✓Bag volume is entered in cubic feet.
- ✓Existing mulch depth is not automatically subtracted.
03 / Worked example
See the math in context
A 300-sq-ft bed at 3 inches deep needs 75 cubic feet, or 2.78 cubic yards, before allowance.
04 / Guidance
Check what is already there
If usable mulch remains, measure its settled depth and add only enough to reach the intended finished layer. Avoid automatically adding the full target depth every year.
Questions
Frequently asked
How do I measure an irregular area?+
Split the bed or lawn into rectangles, circles, and triangles, calculate each area, then add them. Measure narrow curves in shorter sections for a better approximation.
Should I include extra material?+
Use a visible allowance for grade variation, settlement, compaction, spillage, cuts, or future repair as appropriate. The right percentage depends on the material and site.