According to the Border Collie growth chart, this dog is a medium-sized dog of athletic build. Male Border Collies are tall 19 to 22 inches and usually weigh 30 to 55 pounds. Females are slightly smaller in height, with the average height of 18 to 21 inches, while their weight range is the same as in male Collies. Also, there is a smaller version of this dog called the mini Border Collie. This dog’s height goes from 12 to 16 inches, and they weigh 15 to 35 pounds. What is controversial with the mini version of the popular Border Collie dog is the way these dogs are bred. Some breeders will breed runts from their litter, or will mate a smaller dog breed with a Border Collie to get a smaller version of this intelligent dog. So, many mini Border Collies are actually not purebred, but mixed dogs. These dogs are not registered with any of the official kennel clubs. Just like standard Border Collies, these mini dogs are also intelligent, loyal, and energetic. Many breeders find breeding mini dogs like this one unethical, since these dogs might be more prone to specific health problems. So, if you would like to have a Border Collie in a smaller edition, we suggest you do an even more thorough research, and ask the breeder all questions about your dog’s origin.