How big do Border Collies get?
Border Collies average between 30 to 50 pounds. However, if size is important to you, be aware that some Border Collies are as small as 25 pounds, and some are as large as 65 pounds. You can usually tell how big a dog will get by looking at his parents, but if you plan to get a puppy and you need or want a dog whose size you can count on, you might want to consider a breed with less variation in size.