Use the common estimate: dog years = 7 × human years
For a more accurate estimate, use the dog’s size and breed
Small dogs age more slowly than large dogs
Large dogs age more quickly than small dogs
A simple modern formula is: dog age in human years = 16 × ln(dog age in years) + 31
For puppies, the first year is about 15 human years
The second year is about 9 more human years
Each year after that is about 4 to 5 human years
Compare the result with a breed-specific age chart for better accuracy