Border Collies are a medium sized breed. Though the can range in size they are usually fairly consistent. Border Collies have short legs which allow them to crouch easily.
The appearance of the dog should be athletic and well balanced. Medium sized is standard with traits that show equal amounts of strength, agility, style and soundness. The body should appear muscular and hard given the impression of incredible stamina and effortless movement.
A fully grown Border Collie will range from 18 to 22 inches tall at the withers. Males are typically 19 to 22 inches tall and females 18 to 21 inches tall.
Strong bones of medium to light are greatly preferred over heavier boned dogs in the breed. Excessive weight is a big fault and any area of the body that is out of proportion is also a fault. These dogs need to be strong working order and appear strong and fit.