Cat Age Calculator
A two-year-old cat is about 24 in human years — but that number depends on which source you read. International Cat Care and the Cornell Feline Health Center publish two different, equally respected conversions, and this calculator shows both.
In human years, your cat is about…
24
human years — for a 24-month-old cat (2 years).
This figure follows the International Cat Care table. The Cornell Feline Health Center publishes a different one — 3 human years lower for any cat past its second birthday. Neither is wrong: a cat's “human age” is a convention agreed between veterinary organizations, not a measurement.
Cat age chart: cat years to human years
| Cat age | International Cat Care | Cornell |
|---|---|---|
| 1 month | 1 | — |
| 2 months | 2 | — |
| 3 months | 4 | — |
| 4 months | 6 | — |
| 5 months | 8 | — |
| 6 months | 10 | — |
| 7 months | 12 | — |
| 12 months | 15 | — |
| 18 months | 21 | — |
| 24 months | 24 | 21 |
| 3 years | 28 | 25 |
| 4 years | 32 | 29 |
| 5 years | 36 | 33 |
| 6 years | 40 | 37 |
| 7 years | 44 | 41 |
| 8 years | 48 | 45 |
| 9 years | 52 | 49 |
| 10 years | 56 | 53 |
| 11 years | 60 | 57 |
| 12 years | 64 | 61 |
| 13 years | 68 | 65 |
| 14 years | 72 | 69 |
| 15 years | 76 | 73 |
| 16 years | 80 | 77 |
| 17 years | 84 | 81 |
| 18 years | 88 | 85 |
| 19 years | 92 | 89 |
| 20 years | 96 | 93 |
| 21 years | 100 | 97 |
| 22 years | 104 | 101 |
| 23 years | 108 | 105 |
| 24 years | 112 | 109 |
| 25 years | 116 | 113 |
Both columns are human years. After 2 years, each source adds 4 human years for every cat year, which is why they stay exactly 3 apart. Cornell publishes no figure for a kitten under 2, so those rows are left blank rather than filled in with a number the source does not give.
The chart stops at 25 years — International Cat Care publishes nothing beyond that age, so this calculator holds the same figure for any older cat rather than extending the curve past what the source supports. If your cat is 25 or older, that is why the number stops moving.
How long do cats live?
Teng et al. (2024) built a life table from 7,936 cat deaths recorded by UK vets: life expectancy at birth was 11.74 years — 12.51 for females and 11.18 for males. Breed moved it further still: the Burmese reached 14.42 years and the Sphynx 6.68. These are British cats; we have not found an equivalent table built on American records.
The Cornell Feline Health Center, which supplies the second column of the chart above, publishes no life expectancy at all on its senior-cat pages — only that it is no longer unusual for a veterinarian to see cats in their twenties. Figures of “12 to 18 years” are widely attributed to Cornell; they are not on those pages, so this site does not repeat them.
Common questions
How old is my cat in human years?
A one-year-old cat is about 15 in human years, and a two-year-old about 24. After that, International Cat Care adds 4 human years for every cat year — so a ten-year-old cat is about 56.
Why do different websites give different answers?
Because there is no single published conversion. International Cat Care puts a two-year-old cat at 24 human years; the Cornell Feline Health Center puts it at 21. Both then add 4 years per year, so the two stay exactly 3 human years apart for the rest of the cat's life. This calculator uses the International Cat Care table and shows you the Cornell figure beside it.
Is the “multiply by seven” rule true for cats?
No. It would make a one-year-old cat seven in human years, where both published tables put it near 15. Cats do most of their growing up in the first two years, and far less in each year after.
Is this a measurement?
No, and that matters. These numbers are a convention agreed by veterinary organizations to describe life stages, not a measurement of biological age. That is why two respected sources can differ by 3 human years and neither is wrong.
How old is a kitten in human years?
International Cat Care publishes the first year month by month: a 4-month-old kitten is about 6 in human years, and a 6-month-old about 10. That is why a kitten can behave like a small child one month and a teenager the next.
How long do cats live?
Teng et al. (2024) built a life table from 7,936 cat deaths recorded by UK vets: life expectancy at birth was 11.74 years — 12.51 for females, 11.18 for males. Among the breeds it could analyse, the Burmese reached 14.42 years and the Sphynx 6.68. These are British cats. The Cornell Feline Health Center, which supplies the second column of the chart on this page, publishes no life expectancy at all on its senior-cat pages — so the “12 to 18 years” often attributed to it is not repeated here.
This figure is a published convention for describing life stages, not a measurement of your cat's biological age. It does not replace a veterinary exam.
Verified on . Based on Life tables of annual life expectancy and risk factors for mortality in cats in the UK (Teng et al., Journal of Feline Medicine and Surgery (2024), 26(5), VetCompass — 7,936 deaths), Obesity in Cats — overweight threshold and why ideal weight varies (International Cat Care, updated 26 September 2025), Cat pregnancy — how long pregnancy lasts in cats (International Cat Care, accessed 2026-07-30 (golden-test source, not used to build the calculation)), How old is your cat? — life stage and human equivalent age (International Cat Care (Cat Friendly Clinic), accessed 2026-07-28) and The Special Needs of the Senior Cat — cat age in human years (Cornell Feline Health Center, Cornell University, accessed 2026-07-28 (golden-test source, not used to build the calculation)). See the method.