However, as a general guideline, the American Veterinary Medical Association breaks it down as follows: 15 human years equals the first year of life for a medium-sized dog. The second year for a dog is about nine years for a human. And after that, every human year would be about five years for a dog.
A general rule of thumb for dog owners is that one year for dogs is equal to seven human years. But new research shows that young puppies age much faster than young humans, so the simple ratio of one to seven years is wrong. A 1-year-old dog is more “like a 30-year-old human,” said one scientist.
Using a dog age chart to estimate your dog’s age in human years is a fun and insightful way to learn more about him! It’s important for other reasons too. Namely, understanding how old your dog is and how he is aging will enable you to properly care for him – and help him live the best life possible.
So a 7-year-old dog would be about 62.1 human-years old.
With this formula, a 10-year-old dog is equivalent to a 53-year-old human. Using the simple 7:1 ratio, the same 10-year-old dog would be equivalent to a 70-year-old human. All of these calculations are based on the assumption that the average life expectancy of people in developed countries is 80 years.
Depending on its size, a 16-year-old dog corresponds roughly to an 80- to 123-year-old human. Like older people, your dog will move more slowly and sleep more than in his livelier years. He may also be showing signs of cognitive decline.
Below is a guide based on breed size: Small breeds are considered older dogs around 10-12 years of age. Medium breeds are considered older dogs at around 8-9 years old. Large and giant breeds are considered older dogs around 6-7 years of age.
Depending on the breed and size of the dog, ages 10 to 12 are late middle age and beginning of old age.
But why do our beloved pets live so much shorter lives than our own, regardless of their size? Well, dogs have faster metabolisms and hearts that work harder than our own. Because of all this extra work, dogs age faster and consequently live shorter lives. It also means they grow up faster.