Cat Age Calculator
Convert your cat's age into human years with the standard veterinary formula.
How Old Is Your Cat in Human Years?
How Cat Years Are Calculated
Cats race through kittenhood: the first year equals about 15 human years and the second adds about 9 more, so a 2-year-old cat is roughly 24. From then on, each cat year adds about 4 human years. Unlike dogs, size barely matters — most cats fall within a narrow weight band, so a single formula fits nearly all breeds.
| Cat's age | Human years | Life stage |
|---|---|---|
| 6 months | ~10 | Kitten |
| 1 year | 15 | Junior |
| 2 years | 24 | Junior |
| 5 years | 36 | Adult |
| 8 years | 48 | Mature |
| 11 years | 60 | Senior |
| 15 years | 76 | Senior |
| 20 years | 96 | Geriatric |
Comparing a multi-pet household? Try the dog age calculator too, or check feeding needs with the dog calorie calculator.
Frequently Asked Questions
How old is a 1-year-old cat in human years?
About 15. Cats reach the feline equivalent of young adulthood within their first year.
How old is a 10-year-old cat in human years?
About 56 — 24 for the first two years, plus 4 per year for the next eight.
Do indoor cats age slower than outdoor cats?
The biological formula is the same, but indoor cats live far longer on average — often 12–18 years versus 2–5 for outdoor-only cats — because they face fewer hazards.