Measure the length, width, and thickness of the area in feet
Multiply length × width × thickness to get cubic feet
Divide the cubic feet by 27 to get cubic yards
Use the formula: cubic yards = (length × width × thickness) ÷ 27
If thickness is in inches, divide by 12 first to convert to feet
Add extra concrete for waste, spillage, and uneven ground
Round up to the next tenth or quarter yard when ordering
For multiple sections, calculate each section separately and add them together