How Old is My Cat?

We've all heard the old adage that a year in human-years is worth seven years in a dog's life. That's not entirely accurate, but is a good rule of thumb. But what about cats?

As it turns out, the figures are not quite the same for our feline companions. Various sources contain different absolutes for this, but if one human year is a certain multiple in cat-years, it would stand to reason that each year should be a range of cat ages. So a cat who is 5 years and 0 months old would be younger than a cat who's 5 years and 11 months old. Not to mention that a cat who is living rough outdoors has a lower life expectancy, and thus would age faster, than its indoor cousins.

In aggregating all the various sources for domestic cats' ages, I've come up with a table that provides a nice range of feline ages for each year in a human's life, and also provides a separate range for outdoor cats. Because cats mature quickly in kittenhood, the first year is broken down further into months. 

While cats are living longer, thanks to more being kept indoors, better food, and more advanced veterinary care, none of the sources I've found provide anything above 25 human years. So this table stops with that, even though there are some cats who live beyond 25 human years. I've also provided guidelines for what's considered the various stages of a cat's life, and what health issues to watch for in those stages.

Age Chart for Cats

Sources

For more complete information on the health conditions mentions in the chart, consult the source material directly:

Pet MD, "6 Kitten Health Issues to Watch For"; The Spruce Pets, "Common Disorders and Diseases in Kittens"; Pet MD, "The 5 Most Common Kitten Illnesses"; Fetch by Web MD, "6 Most Common Cat Health Problems"; Cornell University College of Veterinary Medicine, "Feline Dental Diseases"; Petfinder, "Top 5 Serious Cat Illnesses Only Your Vet Can Diagnose"; Vetstreet, "Senior Cats: What to Expect at 13-15 Years"; Vetbabble, "Liver Disease in Cats. Common Causes, Symptoms and What to Expect"; PetMD, "Seven Most Common Illnesses in Senior Cats"; Vetstreet: "Senior Cats: What to Expect at 10-12 Years"; Cornell University College of Veterinary Medicine, "Gingivostomatitis"; PetMD, "Cancer in Cats: Symptoms, Types and Treatment"