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Cat Age Calculator
Find your cat's age in human years with International Cat Care's chart, and see its life stage by the AAHA and AAFP feline guidelines.
Cat Age Calculator: International Cat Care counts the first two years of a cat's life as 24 human years, 15 of them in the first year, and every year after as 4 human years. The life stage follows the 2021 AAHA/AAFP Feline Life Stage Guidelines: kitten to 1 year, young adult 1 to 6, mature adult 7 to 10, and senior over 10. Runs 100% locally in your browser with zero server file uploads.
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About 28 in human years
Young adult15 at one year, 24 at two, then 4 human years for every cat year, as International Cat Care counts it.
- Kittenbirth to 1 year
- Young adult1 to 6 years
- Mature adult7 to 10 years
- Seniorover 10 years
| Cat's age | Human age |
|---|---|
| 6 months | 10 |
| 1 y | 15 |
| 2 y | 24 |
| 3 y | 28 |
| 4 y | 32 |
| 5 y | 36 |
| 6 y | 40 |
| 7 y | 44 |
| 8 y | 48 |
| 10 y | 56 |
| 12 y | 64 |
| 14 y | 72 |
| 16 y | 80 |
| 18 y | 88 |
| 20 y | 96 |
How the chart counts
International Cat Care's chart follows a cat's development: by its first birthday a cat is close to its adult size and able to breed, which it treats as about 15 human years, and by two it is a young adult of about 24. From then on each year adds about 4, so a 10-year-old cat is about 56 and a 20-year-old about 96. Ages in between the chart's rows, such as nine months, are read proportionally between them.
The months in the first year move fastest: a two-month-old kitten is about 2, a six-month-old about 10, the age at which many cats become able to breed.
Life stages for care
The 2021 guidelines from the American Animal Hospital Association and the American Association of Feline Practitioners divide a cat's life into kitten, young adult, mature adult, and senior, plus an end-of-life stage that can come at any age. The stages set what a vet checks for: vaccinations and neutering for kittens, weight and dental health in adulthood, and kidney function, blood pressure, and arthritis in seniors.
For a dog, the dog age calculator shows two methods side by side.
How to use it
- Enter your cat's age in years and months.
- Read the age in human years and the life stage.
- Use the table to compare ages from 6 months to 20 years.
Privacy & limitations
Everything is calculated in your browser; nothing is stored.
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Frequently asked questions
How old is my cat in human years?
A one-year-old cat is about 15 in human years and a two-year-old about 24. After that, add 4 for each year: a 10-year-old cat is about 56 and a 15-year-old about 76.
When is a cat a senior?
The 2021 AAHA/AAFP guidelines call cats over 10 years old seniors, and recommend a vet check at least once a year at every age. Older cats often hide illness, so changes in weight, thirst, or behaviour are worth mentioning to the vet.
How long do cats live?
International Cat Care gives an average of around 12 to 14 years, and many cats reach their late teens or early twenties, especially indoor cats with regular care.
Why is the first year worth so much?
In their first year cats grow from newborn to adult size and become able to breed, the development that takes a person into their mid-teens. After about two years they age more steadily.
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