Cat age to human years chart
A 1-year-old cat is about 15 in human years, a 2-year-old about 24. After that, each year adds about 4 human years: a 10-year-old cat is about 56, a 16-year-old about 80.
| Cat's age | Human age | Life stage |
|---|---|---|
| 6 months | 10 years | Kitten |
| 1 year | 15 years | Adult |
| 2 years | 24 years | Adult |
| 3 years | 28 years | Adult |
| 4 years | 32 years | Adult |
| 5 years | 36 years | Adult |
| 6 years | 40 years | Adult |
| 7 years | 44 years | Adult |
| 8 years | 48 years | Adult |
| 9 years | 52 years | Adult |
| 10 years | 56 years | Adult |
| 11 years | 60 years | Senior |
| 12 years | 64 years | Senior |
| 13 years | 68 years | Senior |
| 14 years | 72 years | Senior |
| 15 years | 76 years | Senior |
| 16 years | 80 years | Senior |
| 17 years | 84 years | Senior |
| 18 years | 88 years | Senior |
| 19 years | 92 years | Senior |
| 20 years | 96 years | Senior |
Kitten age in human years, month by month
The first year isn't spread evenly: a kitten grows up very fast in its first months, then more slowly. We follow the chart in the AAFP and AAHA feline guidelines: a 3-month-old kitten is about 4 in human years, a 6-month-old about 10 and a 1-year-old cat about 15.
| Kitten's age | Human age |
|---|---|
| 2 months | 3 years |
| 3 months | 4 years |
| 4 months | 7 years |
| 5 months | 9 years |
| 6 months | 10 years |
| 7 months | 12 years |
| 8 months | 13 years |
| 9 months | 13 years |
| 10 months | 14 years |
| 11 months | 14 years |
How to calculate your cat's age in human years
It takes three steps, from your cat's age.
- Count 15 years for the first yearA 1-year-old cat is about 15 in human years. For a kitten, count about 4 years at 3 months, 10 at 6 months and 12 at 7 months.
- Add 9 years for the second yearAt 18 months, a cat is about 21 in human years, and at 2 about 24.
- Then add 4 years a yearFor each year after the second, add about 4 human years.
Example: a 10-year-old cat is about 24 + 8 × 4 = 56 in human years.
Convert human years to cat years
The reverse calculation: at what age will your cat be 40, 60 or 80 in human years?
Example for 40 human years, a cat is about:
6 years
| Human age | Cat's age |
|---|---|
| 12 years | 7 months |
| 15 years | 1 year |
| 20 years | 1 year and 5 months |
| 24 years | 2 years |
| 30 years | 3 years and 6 months |
| 40 years | 6 years |
| 50 years | 8 years and 6 months |
| 60 years | 11 years |
| 70 years | 13 years and 6 months |
| 80 years | 16 years |
The "one pet year equals seven human years" myth
This simple rule is wrong. Dogs and cats become adults in barely one to two years, then age more slowly. One early year of life is worth far more than seven human years, while a year late in life is worth less.
Cat life expectancy
A 2023 study based on the records of more than two million cats seen at US veterinary clinics gives a life expectancy at birth of 11.2 years.
That figure includes cats that die young: once past its first years, a cat's total life expectancy is longer. Build matters little in cats, which is why one curve fits them all.
The main life stages
Understanding your pet's life stage helps you adapt its diet, activity and health care.
Kitten
Fast growth: vaccines, deworming and identification are essential. Consider neutering as soon as your vet advises it.
Adult
Prime years: one vet visit a year, a suitable diet and regular activity are enough to keep them healthy.
Senior
Watch weight, teeth and joints. Two vet visits a year help catch health issues early.
An estimate, not a diagnosis
This calculator gives a ballpark figure. Every animal ages at its own pace, and only a vet can properly assess its health.
Our sources
- Method (cat), from kitten to old age (4 at 3 months, 10 at 6 months, 15 at 1 year, 21 at 18 months, 24 at 2 years, then 4 years a year): the chart in the AAFP-AAHA feline life stage guidelines, Hoyumpa Vogt et al., Journal of Feline Medicine and Surgery, 2010. doi.org
- Dog and cat life expectancy: Montoya et al., "Life expectancy tables for dogs and cats derived from clinical data", Frontiers in Veterinary Science, 2023 (US veterinary clinic records, figures checked on 31 October 2026). doi.org
- Cat life stages: the AAHA / AAFP feline life stage guidelines, 2021. catvets.com
Going further
Welcoming an animal well also means planning ahead and being ready to react.
FAQ - Frequently asked questions
How old is a 1-year-old cat in human years?
About 15. Its first year covers a whole human childhood and adolescence, which is why the simple times-seven rule is wrong.
How old is a 6-month-old kitten in human years?
About 10. A kitten grows up very fast in its first months, then the pace slows. The AAFP and AAHA feline guidelines put 3 months at about 4 human years, 6 months at 10 and 7 months at 12, then 1 year at 15.
How old is a 10-year-old cat in human years?
About 56. After its first two years, worth about 24 human years, a cat adds about 4 human years a year. The chart on this page gives the year-by-year equivalent.
How old is a 15-year-old cat in human years?
About 76. After its first two years, worth about 24 human years, a cat adds about 4 human years a year: 24 + 13 × 4 = 76.
How old is a 16, 17 or 18-year-old cat in human years?
About 80 at 16, 84 at 17 and 88 at 18. The chart on this page goes up to age 20, about 96 in human years.
At what age is a cat considered old?
The AAHA and AAFP feline guidelines (2021) put a cat in its senior stage after 10. From then on, a vet check at least once a year helps catch kidney, dental or joint issues early.
How long do cats live?
11.2 years on average at birth, according to a 2023 study of more than two million cats seen at US veterinary clinics. That figure includes cats that die young: once past its first years, a cat's total life expectancy is longer.
How do I convert human years to cat years?
Up to 15 human years is its first year: 4 human years is a 3-month-old kitten, 10 is 6 months and 12 is 7 months. From 15 to 24 human years is its second year: 21 human years is 18 months. Beyond that, subtract 24, divide by 4 and add 2. For example, 40 human years is a cat of about 6.
Do the cat's size or breed matter?
Far less than for dogs. So we use a single ageing curve for all cats, which holds in the vast majority of cases.
Does this replace the vet?
No. It's an estimate to help you understand your cat's life stage. Only a vet can properly assess its health and true age.