It turns out some parts of a dog’s life follows the same pattern as humans, though other longevity milestones don’t link up quite as nicely

A STUDY OF THE EPIGENETIC CLOCK IN LABRADORS SHOWS CALCULATING A DOG'S AGE IS MUCH MORE COMPLICATED THAN JUST MULTIPLYING BY SEVEN

For instance, the methylation rate showed a seven-week-old pup corresponds to a 9-month-old human baby, and both species begin to get their first teeth at this time.

But the comparison breaks down after early puppyhood. The dog clock ticks much faster with pups speeding through puberty and reaching sexual maturity within their first year. Then, the dog's epigenetic clock slows down as the dog ages, and begins to match up with humans again in its later years.

According to the formula, a 2-year-old dog is the equivalent of a 42-year-old human, but things slow down after that. A 5-year-old dog is the equivalent of a 56.75 year old human, and a 10-year-old dog is the equivalent of 67.8-year-old person.

[human_age = 16ln(dog_age) + 31]

Find more info about this study Here.

Of course the rate of maturity and life expectancy vary depending on the dog’s size and breed. The above is for Labradors.

Small dogs reach skeletal and reproductive maturity sooner than larger breeds, which means that they grow up faster than bigger dogs. At the age of one, a small dog might have reached its full adult size a but a larger dog breed will likely still be growing.

For the first few years of life, small dogs mature much faster than bigger dogs. After the first few years, however, their rate of growth slows down.