How cat years are counted
The calculator uses the Feline Life Stages chart, a client handout released with the 2021 AAHA/AAFP Feline Life Stage Guidelines of the American Animal Hospital Association and the American Association of Feline Practitioners (both linked on catvets.com/life-stage). A cat ages fast at first: 15 human years by its first birthday and 24 by its second. After that, every cat year adds 4 human years.
| Cat age | Human age |
|---|---|
| 1 month | 1 years |
| 3 months | 4 years |
| 6 months | 10 years |
| 1 year | 15 years |
| 2 years | 24 years |
| 3 years | 28 years |
| 4 years | 32 years |
| 6 years | 40 years |
| 7 years | 44 years |
| 8 years | 48 years |
| 9 years | 52 years |
| 10 years | 56 years |
| 11 years | 60 years |
| 12 years | 64 years |
| 13 years | 68 years |
| 14 years | 72 years |
| 15 years | 76 years |
| 16 years | 80 years |
| 17 years | 84 years |
| 18 years | 88 years |
| 19 years | 92 years |
| 20 years | 96 years |
| 21 years | 100 years |
| 25 years | 116 years |
The chart skips 5 years and 22 to 24 years, and it has no values between whole ages. For those, the calculator draws a straight line between the two nearest chart ages and says so with the result. A cat of 5 comes out at 36, halfway between 32 and 40.
Feline life stages
The 2021 guidelines reduced the earlier six life stages to four age-based stages. A fifth stage, end of life, can come at any age.
| Life stage | Cat age | Vet checkups |
|---|---|---|
| Kitten | birth up to 1 year | at least once a year |
| Young adult | 1 through 6 years | at least once a year |
| Mature adult | 7 to 10 years | at least once a year |
| Senior | over 10 years | at least every 6 months |
The guidelines stress that any age groupings are arbitrary marks along a spectrum, not absolutes, and that individual cats vary a lot. The checkup intervals are the minimums the guidelines recommend; cats with chronic conditions may need more visits.
How to use the cat age calculator
- 1Enter your cat's age in years, and months if you know them. For a kitten, leave years empty or at 0 and enter the months.
- 2Read the age in human years and the life stage, with its checkup interval.
- 3Copy the result or a link to it. For a dog, use the dog age calculator, and for your own exact age the age calculator.
Frequently asked questions
How old is my cat in human years?
On the Feline Life Stages chart that came with the 2021 AAHA/AAFP guidelines, a 1-year-old cat equals a 15-year-old human and a 2-year-old cat a 24-year-old. From there, every cat year adds 4 human years: 28 at 3, 40 at 6, 56 at 10, 76 at 15 and 96 at 20.
When is a cat a senior?
The 2021 AAHA/AAFP Feline Life Stage Guidelines call a cat senior when it is over 10 years old. They also note that age groupings are arbitrary marks along a spectrum, and a senior cat in excellent condition may be treated as a mature adult at the veterinarian's discretion.
What are the life stages of a cat?
The guidelines use four age-based stages: kitten, from birth up to 1 year; young adult, 1 through 6 years; mature adult, 7 to 10 years; and senior, over 10 years. A fifth stage, end of life, can come at any age.
Is one cat year seven human years?
The chart does not use a fixed factor. The first year counts as 15 human years and the second as 9 more, then each year adds 4. A 10-year-old cat is 56 on the chart, not 70.
How often should my cat see a vet?
The guidelines recommend a full examination at least once a year for all cats and at least every 6 months for senior cats, more often for cats with chronic conditions.
Is my data sent anywhere?
No. The calculation runs in your browser, nothing is stored or sent.