Cat age in human years

How cat years are converted

Cats grow up very quickly in their first year: at 1 month a cat is like a 1-year-old child, at 3 months like a 4-year-old, at 6 months like a 10-year-old, and at 12 months it is already the equivalent of a 15-year-old teenager; at 2 years it reaches 24. After that, aging levels off and the chart adds 4 human years for each year of a cat's life: 40 at 6 years, 56 at 10, 76 at 15, 96 at 20. Between two points of the chart, the calculator goes in a straight line. Unlike dogs, body size makes little difference: a well-cared-for indoor cat typically lives 12 to 16 years, and it's not unusual for one to pass 20, the equivalent of nearly a full human century.

A cat's life stages

The 2021 AAHA/AAFP guidelines recognize four stages: kitten (from birth to 1 year), young adult (1 to 6 years), mature adult (7 to 10) and senior (10 and up), plus an end-of-life stage that can come at any age and so cannot be worked out from the years. The 2010 guidelines, still quoted in many places, counted six, with junior and geriatric: they have been replaced. Here a stage lasts until the next birthday: at 9 and a half a cat is still a mature adult, and it becomes a senior once it turns 10. Knowing the stage helps you pick the right food and schedule check-ups: up to 10 at least one visit a year, as a senior at least one every six months, since kidneys and the thyroid are the weak spots of aging cats. The stages are those of the guidelines, and the human years come from the chart of the FelineVMA, the association of cat vets that wrote them. For dogs there is Dog Age in Human Years. This tool provides estimates only and is not a substitute for advice from a licensed veterinarian.