Rio Stone field guide
Cubic yards and material coverage
Use area, depth, and unit conversions correctly, then preserve the calculation so a material specialist can review it.
A useful material request starts with a clear measurement, a defined use, and honest expectations about what still needs confirmation.
Start with net area
Rectangle area is length × width; triangle area is base × height ÷ 2; circle area is π × radius². Add the shapes that receive the same material and depth, then subtract buildings, large planters, or other excluded surfaces. Irregular borders are easier to audit when divided into smaller shapes instead of estimated as one bounding rectangle.
Move from area to cubic yards
Multiply square feet by depth in inches and divide by 324. For example, 500 sq ft at 2 in deep equals 1,000 ÷ 324, or 3.09 yd³ before allowances. The equivalent long method is area × depth in feet ÷ 27. Both formulas describe geometric volume, not weight, compaction, or the supplier's sale increment.
Understand coverage tables
Coverage is another expression of volume and must state a depth. One cubic yard spread 1 inch deep covers 324 sq ft geometrically; at 2 inches it covers 162 sq ft; at 3 inches it covers 108 sq ft. Real placement can differ at edges and around large particles, so use the table as a planning check rather than a guarantee.
Keep the final conversion traceable
Write down original dimensions, excluded areas, depth, raw cubic yards, each allowance, and the final proposed quantity. If the product is sold by bag, pallet, half-yard, or another increment, use verified package content and round up only at that final step. Ask Rio to reconcile the calculation with the exact product and fulfillment method.
Before requesting pricing
- Calculate net area by shape and keep zones with different depths on separate lines.
- Convert depth to feet or use the direct square-feet × inches ÷ 324 formula for cubic yards.
- Round only after Rio confirms the product's sale unit and the reason for any additional material.
Frequently asked questions
How many cubic feet are in one cubic yard?
Twenty-seven cubic feet. That conversion is exact, but it does not determine weight or field coverage after compaction and settlement.
Can I add 10% to every project?
No universal percentage fits every job. Cuts, irregular borders, compaction, settlement, and spare material should be evaluated separately.
Why does a supplier quantity differ from my geometry?
The product may have a sale increment, verified coverage, compaction behavior, moisture condition, or practical load constraint that geometry alone does not capture.