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Cat age calculator
Convert your cat's age to human years and see which life stage it's in.
How the calculator works
Cats grow up fast. A six-month-old kitten is about as developed as a 10-year-old child, a one-year-old cat is like a 15-year-old, and a two-year-old is like a person of 24. After that, each cat year adds about 4 human years.
The calculator follows the cat age chart in the feline life stage guidelines from the American Association of Feline Practitioners (AAFP) and the American Animal Hospital Association (AAHA), and fills in between the chart's ages for part years. Cat size and breed make far less difference than they do in dogs, so there's one chart for every cat.
Cat age chart
| Cat age | Human years | Life stage |
|---|---|---|
| 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 |
Source: AAFP–AAHA Feline Life Stage Guidelines cat age chart (6 months to 21 years). Life stages from the 2021 update.
Life stages
The 2021 AAHA/AAFP Feline Life Stage Guidelines group a cat's life into four stages:
- Kitten: birth to 1 year.
- Young adult: 1 to 6 years.
- Mature adult: 7 to 10 years.
- Senior: over 10 years.
Regular vet checkups matter at every stage. Cats often hide illness well, especially as they get older, so changes in appetite, thirst, weight or litter box habits are worth mentioning to your vet.
Is one cat year seven human years?
No. A one-year-old cat is fully grown and can breed, more like a teenager than a seven-year-old child. Cats then age more slowly than that early burst suggests, about 4 human years for each cat year.
Not sure how old your cat is? A vet can estimate it from the teeth, eyes and coat. The estimate is usually close for kittens and young cats, and rougher for adults.
Common questions
How old is a 1-year-old cat in human years?
About 15. A cat does most of its growing up in the first year.
How old is a 2-year-old cat in human years?
About 24. From here on, each cat year adds about 4 human years.
How old is a 10-year-old cat in human years?
About 56. Under the 2021 guidelines, a cat is a senior after age 10.
How old is a 15-year-old cat in human years?
About 76.
How old is a 20-year-old cat in human years?
About 96. Plenty of indoor cats now reach their late teens.
Have a dog too? Try the dog age calculator.
Sources: Hoyumpa Vogt A, Rodan I, Sparkes A et al. (2010), “AAFP–AAHA Feline Life Stage Guidelines”, Journal of Feline Medicine and Surgery 12: 43–54. Quimby J, Gowland S, Carney HC et al. (2021), 2021 AAHA/AAFP Feline Life Stage Guidelines. An estimate, not veterinary advice.