Stone size, shape, gradation, moisture, and void space affect weight and visual coverage, so this calculator reports dependable geometric volume.
01 / Formula
How this is calculated
Cubic yards = area sq ft × depth in ÷ 324 × (1 + allowance %)02 / Assumptions
What the estimate assumes
- ✓Area and finished depth are uniform.
- ✓Weight is intentionally excluded.
- ✓Edging displacement and existing material are not automatically subtracted.
03 / Worked example
See the math in context
A 240-sq-ft bed at 2 inches deep contains 40 cubic feet, or 1.48 cubic yards before allowance.
04 / Guidance
Request product-specific coverage
Decorative aggregate suppliers often publish coverage or weight guidance for each product. Use that source to translate this volume into the supplier’s selling unit.
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.