Concrete is sold by volume, typically in cubic yards (for truck deliveries) or cubic feet (for pre-mixed bags). Calculating the exact amount needed is crucial because ordering too little stops the job cold, while ordering too much wastes money and creates disposal headaches.

The Basic Formula

The core formula for concrete volume is simple geometry: Length × Width × Depth.
However, the challenge lies in unit conversion. Most projects are measured in feet and inches, but concrete is sold by the cubic yard.

Why divide by 27? Because a cubic yard is 3 feet wide, 3 feet long, and 3 feet deep (3 × 3 × 3 = 27 cubic feet).