How to convert cat years to human years
Cats grow up fast. By their first birthday they are like a 15-year-old teenager, and by two they are young adults of about 24. From then on, each cat year equals about 4 human years.
Year 2 = 24 human years
After that: human age = 24 + 4 × (cat age − 2)
Cat age chart
| Cat age | Human years | Life stage |
|---|---|---|
| 3 months | 4 | Kitten |
| 6 months | 10 | |
| 9 months | 13.5 | |
| 1 year | 15 | Young adult |
| 2 | 24 | |
| 3 | 28 | |
| 4 | 32 | |
| 5 | 36 | |
| 6 | 40 | |
| 7 | 44 | Mature adult |
| 8 | 48 | |
| 9 | 52 | |
| 10 | 56 | Senior |
| 12 | 64 | |
| 15 | 76 | |
| 18 | 88 | |
| 20 | 96 |
Cat life stages
- Kitten (birth to 1 year): fast growth, vaccines, spay or neuter.
- Young adult (1 to 6 years): peak health. Yearly checkups and weight control.
- Mature adult (7 to 10 years): like people in their 40s and 50s. Dental disease and weight gain become common.
- Senior (over 10 years): checkups every 6 months, with blood and urine tests for kidney disease, thyroid problems and diabetes.
How long do cats live?
Indoor cats usually live 13 to 17 years, and many reach their 20s. Outdoor cats have shorter lives on average because of traffic, fights and disease. The oldest recorded cat, Creme Puff, lived to 38.
Feeding an older cat? Check daily calories with the cat food calculator. For dogs, use the dog age calculator.
Sources: 2021 AAHA/AAFP Feline Life Stage Guidelines; the human age equivalents used by the American Association of Feline Practitioners.
Frequently asked questions
How old is my cat in human years?
Count 15 human years for the first year, 24 for two years, and add 4 for every year after that. A 10-year-old cat is about 56 in human years.
Is one cat year equal to seven human years?
No. Cats mature much faster in the first two years and then age about 4 human years per cat year.
At what age is a cat a senior?
Vets consider cats seniors from about 10 years of age, which is roughly 56 in human years.
How old is a 15-year-old cat in human years?
About 76.
How long do indoor cats live?
Usually 13 to 17 years, and many live into their 20s with good care.
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Last updated October 2026.