Formula used
Cubic yards = square feet × (depth in ÷ 12) ÷ 27; order yards = cubic yards × (1 + allowance ÷ 100)
Reference basis: fixed unit conversions follow the NIST SI conversion tables. Bulk density is product- and condition-specific; the FHWA Field Materials Manual documents aggregate sampling and moisture-density testing; supplier or project data for the actual product and condition should replace the planning preset when available. The USGS aggregates program is used for aggregate terminology and scope. Read the full methodology and limitations.
Worked area-to-volume example
Example values: a measured 600 ft² surface at 3 in deep gives 600 × (3 ÷ 12) ÷ 27 = 5.56 yd³. With no ordering allowance, the result remains 5.56 yd³. The optional 1.35 short tons/yd³ density converts that volume to 7.50 short tons.
What the converted result represents
The entered square footage is preserved in the results so it can be checked against the drawing or takeoff. Density is applied only after the area-and-depth volume is known.
Limits of the geometric model
Variable depth, compaction, settlement, moisture, and supplier density affect material weight even when the geometric volume is correct.
Questions specific to this calculation
Can I convert square feet to cubic yards without depth?
No. Square feet measure area and cubic yards measure volume. Enter the intended depth, or calculate separate zones when depth varies.