Cats and dogs age at rates much faster than humans. Apparently, when a cat has aged 1 year (one year after the cat’s birth), that cat will be <b>15 years old in human years.</b> Then, when a cat turns 2 years old, that cat will be <b>25 years old in human years.</b> From that point onward, the cat will age 4 human years every year. This means that when the cat turns 3 years old, the cat will be 29 in human years, and when the cat turns 4 years old, the cat will be 33 in human years.
Below is a chart I created which represents the age growth difference between cats, dogs and humans. The green line represents the cat growth rate, the blue line represents the dog growth rate, and the red line represents human growth rate. Notice how the cat and dog growth rates are very similar, but that cats grow slightly faster than dogs in their
first two years of life.
One commonly held belief is that cats and dogs age in increments of 7 human years; this is incorrect. Both cats and dogs age rapidly in their first two years of life, and then both age at rates of about 4 human years every year.
Here are cat/dog human age conversion calculator websites: