Cat age calculator: your cat’s age in human years
In shortA 1-year-old cat is roughly 15 in human years, and a 2-year-old cat about 24. After that, each cat year counts for about 4 human years: 7 is 44, 10 is 56, and 15 is 76. This scale comes from American feline veterinary guidelines (AAFP and AAHA) and is an average: every cat ages in his own way.
The chart, year by year
| Age | Human age |
|---|---|
| 1 year | 15 |
| 2 years | 24 |
| 3 years | 28 |
| 4 years | 32 |
| 5 years | 36 |
| 6 years | 40 |
| 7 years | 44 |
| 8 years | 48 |
| 9 years | 52 |
| 10 years | 56 |
| 11 years | 60 |
| 12 years | 64 |
| 13 years | 68 |
| 14 years | 72 |
| 15 years | 76 |
| 16 years | 80 |
| 17 years | 84 |
| 18 years | 88 |
| 19 years | 92 |
| 20 years | 96 |
How it is calculated
The reference scale, published by American feline vets, follows the kitten’s growth: around 6 months he is roughly a 10-year-old child, and may already be sexually mature. At 1 year he is a 15-year-old teenager, at 2 a young adult of 24. After that the pace settles at about 4 human years per year.
It is a practical average for talking about care and behavior, not a biological measurement. A well-cared-for indoor cat and a stray do not age the same way.
A cat’s life stages
The 2021 feline life stage guidelines (AAHA and AAFP) describe four stages. Kitten, up to 1 year: play, exploration, socialization. Young adult, 1 to 6: energy, routines, watch weight and boredom. Mature adult, 7 to 10: metabolism slows, teeth and weight need attention. Senior, over 10: more frequent checkups.
Older cats hide pain well: they jump less high, groom less, change sleeping spots, sleep more or start yowling at night. These are not old-cat quirks but signals to show your vet.
How long do cats live?
A large UK study of cats seen by vets puts a kitten’s life expectancy at about 12 years, a little more for females and crossbred cats. Many cats live much longer: 15 or 18 is nothing unusual, especially for cats kept away from traffic.
Frequently asked questions
Is a 15-year-old cat old?
Yes, it is the equivalent of about 76 human years. Many cats live well beyond that, but at this age a checkup every six months and attention to subtle signs of pain, thirst or weight loss make a real difference.
At what age is a cat a senior?
After 10 years, according to the 2021 feline guidelines. The changes are gradual: he sleeps more, jumps less high, grooms less well and hides pain. Regular checkups catch the common diseases of older cats early.
Do indoor cats age more slowly?
They don’t age more slowly, but they are less exposed to traffic, fights and some diseases, which often lengthens their lives. They do need play, height and stimulation to stay fit.
How can I tell the age of an adopted cat?
Your vet estimates it from the teeth (adult teeth are in by about 6 or 7 months, then tartar and wear build up), the eyes, the coat and the muscles. You get a range, not a birth date.
Sources
The studies this page relies on, with a link to the original publication.
- Vogt et al. (2010). AAFP-AAHA feline life stage guidelines. Journal of Feline Medicine and Surgery.The reference equivalence table: 6 months ≈ 10 human years, 1 year ≈ 15, 2 years ≈ 24, then about 4 human years per cat year.
- Quimby et al. (2021). 2021 AAHA/AAFP feline life stage guidelines. Journal of Feline Medicine and Surgery.Four life stages for cats: kitten (up to 1 year), young adult (1 to 6), mature adult (7 to 10), senior (over 10), each with its own vet check-up.
- Teng et al. (2024). Life tables of annual life expectancy and risk factors for mortality in cats in the UK. Journal of Feline Medicine and Surgery.In the United Kingdom, a kitten seen by vets has a life expectancy of about 12 years; females and crossbred cats live a little longer on average.
Mimo reads behavior. It does not replace a vet.