Dog note: It is a common belief that 1 human year is equal to 7 dog years. That is
not very accurate, since dogs reach adulthood within the first couple of years.
The formula used here is from a canine expert. The formula is: 10.5 dog years per human year for the first 2 years, then
4 dog years per human year for each additional year.
Cat note: There are several models for determining cat years. Experts generally agree that the
first two years of a cat's life are roughly equal to the first 25 of a human's and each additional year
equals approximately four 'cat years'. The formula is: 15 years for the first year, 10 years for the
second year, then 4 cat years per human year for each additional year.