By YardHatch · Published · Updated
Design depth normally describes the installed layer. A supplier may sell loose volume or weight. Ask how that exact aggregate converts before ordering; a generic percentage is only an assumption.
Start from the installed requirement
A modeled 200 sq ft base at 6 inches deep is 200 × 6 ÷ 324 = 3.704 cubic yards compacted. The example does not establish the correct base depth for your site. Traffic, subgrade, climate and manufacturer guidance determine the design.
Name the factor clearly
Here, a 15% loose allowance means multiplying compacted volume by 1.15, giving 4.259 loose cubic yards. That definition differs from saying loose volume shrinks by 15%, which would require division by 0.85 and yield 4.357 yards. Ask which convention the supplier means.
| Step | Formula | Modeled result |
|---|---|---|
| Installed base | 200 × 6 ÷ 324 | 3.704 cu yd |
| Add 15% loose allowance | 3.704 × 1.15 | 4.259 cu yd |
| Alternative 15% shrink definition | 3.704 ÷ 0.85 | 4.357 cu yd |
Use the matching density
If you purchase by US ton, multiply loose cubic yards by pounds per loose cubic yard and divide by 2,000. A compacted density does not belong in that loose-volume calculation. Ask for the material grade and moisture assumptions with the number.
Confirm the order unit on the invoice
Record the installed design, factor convention, supplier conversion and minimum load as separate fields. Verify that delivery volume and truck weight limits both work. Keep the written specification with the project plan so later estimates do not silently use another material.
Make it your own estimate
These are modeled calculations. Actual products, installation conditions and supplier requirements control your order.
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Sources and method
Concrete Masonry & Hardscapes Association: Paver technical guidance provides the relevant background guidance. Worked tables are YardHatch arithmetic using the visible assumptions, not source price data or field observations.