We’ve all heard that one year of human life is equal to seven “dog years.” This may be a fun way for kids to practice multiplication, but it is not a very accurate way to estimate your dog’s “human” age. Dogs’ life spans vary based on their weight and breed (for example, schnauzers generally live longer than bloodhounds) and they reach adulthood much faster than humans. But it’s possible to make an approximate calculation of a dog’s human age based on the following formula.
Assume a medium-sized, 1-year-old dog is the same age as a 15-year-old human. This is because a 1-year-old dog is almost an adult, unlike a 1-year-old baby. In the early years of their lives, dogs mature much faster than people.
Add nine human years for the second year of a medium-sized dog’s life. While a 2-year-old human is just beginning to learn basic social and motor skills, a 2-year-old dog is a sexually mature adult that is no longer learning new skills.
Add five human years for every additional year in the dog’s age. Dogs age faster than humans because they have shorter life spans, so an 8-year-old cocker spaniel is about 54 “human” years old (15 + 9 +30).
This formula is for a medium-sized dog. A large, 8-year-old dog is “older” in human years, and a small 8-year-old dog is “younger.” Calculating a dog’s human age is by no means an exact science. This formula is more for entertainment, though you can use it to gauge how your dog might feel age-wise.