How many cubic yards of concrete are needed for the foundation slab that is 4 inches thick?

• A. 22 cubic yards
• B. 23 cubic yards
• C. 24 cubic yards
• D. 25 cubic yards

Answer: (B)

The amount of concrete for a slab is found by multiplying the footprint area by the thickness, then converting to cubic yards. The slab thickness is 4 inches, which is 1/3 foot. If the slab covers 1863 square feet, the volume in cubic feet is 1863 × 1/3 = 621 ft³. Converting to cubic yards (divide by 27) gives 621 ÷ 27 = 23 yd³. So, 23 cubic yards matches this concrete volume, which corresponds to a footprint of 1863 ft² (for example, 27 ft by 69 ft). The method stays the same: compute area × thickness in feet, then convert from cubic feet to cubic yards.