Off the top-of-my-head, 12 - 15 years.... you can find the official data-based answer on the web I am sure.
My number is for medium sizes dogs in general, not specific to your breed,.
12-16 years is common for border collies. The general 'rule' for dog-lifespans is the bigger the dog, the shorter the lifespan. So while a yorkie might go to 18-20 years, a great dane will live only 8-10 years. Blessings - Blu
Your milage will very greatly between individuals. I've heard of BCs living past 20 and I've known some that didn't make it past the age of five.
Factors that contribute to longevity include genetic makeup (how long have his ancestors lived?) level of activity (couch potato or canine athlete?) and a lot of intangibles.
Border Collies make lousy couch potatoes. They need a great deal of mental and physical stimulus to stay mentally and physically fit. I am convinced that some BCs "gave up" and died early. On the other hand the BCs I see competing in agility live way past the age of ten.
Hi Jerry;
Thank you for your comment! :)
Thank you, BluCrystal, I appreciate it!
Thank you, Salty, good points. I appreciate it!