Cat Age Calculator: Cat Years to Human Years
Enter your cat’s age in years and months to see its age in human years and its life stage, based on the feline life-stage guidelines used by vets.
Adopted a cat and don’t know its age? Try our AI pet age estimator, or for young cats the kitten age calculator.
How to convert cat years to human years
- The first year of a cat’s life equals about 15 human years.
- The second year adds about 9 more – a 2-year-old cat is like a 24-year-old person.
- After that, every cat year equals about 4 human years.
Formula for cats older than 2: human years = 24 + (cat age − 2) × 4. A 10-year-old cat is 24 + 8 × 4 = 56 in human years.
Cat age chart
| Cat age | Human years | Life stage |
|---|---|---|
| 1 month | 1 | Kitten |
| 3 months | 4 | Kitten |
| 6 months | 10 | Kitten |
| 1 year | 15 | Young adult |
| 2 years | 24 | Young adult |
| 3 years | 28 | Young adult |
| 4 years | 32 | Young adult |
| 5 years | 36 | Young adult |
| 6 years | 40 | Young adult |
| 7 years | 44 | Mature adult |
| 8 years | 48 | Mature adult |
| 9 years | 52 | Mature adult |
| 10 years | 56 | Mature adult |
| 11 years | 60 | Senior |
| 12 years | 64 | Senior |
| 13 years | 68 | Senior |
| 14 years | 72 | Senior |
| 15 years | 76 | Senior |
| 16 years | 80 | Senior |
| 17 years | 84 | Senior |
| 18 years | 88 | Senior |
| 19 years | 92 | Senior |
| 20 years | 96 | Senior |
| 21 years | 100 | Senior |
| 22 years | 104 | Senior |
| 23 years | 108 | Senior |
| 24 years | 112 | Senior |
| 25 years | 116 | Senior |
Cat life stages
- Kitten: birth to 1 year
- Young adult: 1 to 6 years
- Mature adult: 7 to 10 years
- Senior: over 10 years
These stages follow the 2021 AAHA/AAFP feline life stage guidelines. From the mature stage on, vets recommend yearly or twice-yearly checkups with blood tests.
How to tell how old a cat is
- Teeth: kittens have all adult teeth by about 6 months. Slight yellowing suggests 1–2 years, tartar on all teeth 3–5 years, and heavy tartar or missing teeth 10 years or more.
- Eyes: young cats have clear, bright eyes; older cats may show cloudy lenses or a lacy-looking iris.
- Coat and muscles: young cats are sleek and muscular; seniors often have a thinner coat and a bonier spine and hips.
Frequently asked questions
How long do cats live?
Indoor cats usually live 12–18 years, and many reach their 20s.
Is 1 cat year really 7 human years?
No. Cats mature very quickly in the first two years and then age at about 4 human years per cat year.