How this calculator works
Multiply area by a perpendicular, uniform depth after converting to compatible units. For square feet and inches, divide depth by 12 to obtain feet, then divide cubic feet by 27 to obtain cubic yards. Reverse modes rearrange the same relation. The geometric result excludes waste, compaction and settlement, so add those separately when estimating an order.
Formula
V(m3) = A(m2) x depth(m); V(yd3) = A(ft2) x depth(in) / 324; A = V / depth; depth = V / A.
Worked example
An 81 ft2 area at 4 in depth contains 27 ft3, exactly 1 yd3. Conversely, 3 m3 spread over 12 m2 makes a uniform layer 0.25 m deep.
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Frequently asked questions
Can square feet be converted directly to cubic yards?
No. Square feet measure area and cubic yards measure volume. A layer depth is required.
Which depth should I use on uneven ground?
Use a measured average depth for a rough estimate or divide the job into zones with separately measured depths.
Does the result include a purchase allowance?
No. This converter reports geometric volume. The appropriate allowance depends on the material and construction method.