The "Drop" is the difference in inches between your chest size and your waist size. Standard off-the-rack suits usually have a fixed "Drop 6" (e.g., a 40" chest comes with 34" trousers). If you have an athletic build (broad shoulders, narrow waist), a standard suit will be too tight in the chest or too loose in the waist. Our custom sizing adjusts the drop to fit your specific body shape.