Convert a known area and layer depth into cubic yards, cubic feet and cubic meters, with an explicit optional allowance and cost.
How to use this tool
- Enter an already checked project area and select ft², yd² or m².
- Enter a uniform depth or thickness with its unit. A positive depth is required.
- If appropriate, enter a chosen allowance and quoted price per cubic yard.
- Select Calculate. Read net volume separately from the allowance scenario; supplier increments remain a separate ordering decision.
Formula and unit basis
yd³ = area(ft²) × depth(in) ÷ 324, or area(ft²) × depth(ft) ÷ 27. The tool converts the selected input units before calculating.
Worked examples
An area of 100 ft² at 4 in depth contains 33.333333 ft³, or 1.234568 yd³. An area of 540 ft² at 6 in depth contains exactly 10 yd³ before allowance.
Assumptions and interpretation
Area alone cannot determine volume; depth is required. The result assumes the entered thickness applies over the whole area. Divide uneven areas into measured zones before adding volumes. An optional allowance does not replace a measured thickness, a material-specific compaction assessment or supplier order increments.
Project guides
- Slab Area and Thickness: A Cubic-Yard Reference You Can Check
- Uneven Depths: Calculate Volume with Zones Instead of a Misleading Average
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Frequently asked questions
Why does the inch-depth formula divide by 324?
It combines 12 inches per foot and 27 cubic feet per cubic yard: 12 × 27 = 324.
Can I use an uneven layer depth?
Calculate meaningful area-depth zones separately, or use a justified area-weighted representative depth.
Is the suggested allowance fixed?
No allowance is suggested. It defaults to zero and is an explicit planning input.