The average age for a dog to die depends on the size of the dog.
Most smaller dogs live up up to 15 to 20 years while other bigger breeds of dogs may only live from 9 to 12 years old.
Smaller dogs have a longer lifespan than larger dogs do but you can usually expect a larger dog to die around age 12 while a smaller dog is likely to die at around 15 to 16 years old but can live as long as 20 years in some cases.