Cat age in human years
Cats age fast at first then slowly: at one year they are already the equivalent of 15 human years, at two years 24. Then the pace settles to roughly four human years per year. Unlike dogs, size makes no difference — domestic cats cover too narrow a weight range for it to matter.
Equivalent human age
28years
Adulte
Most stable period. Monthly weigh-in, annual vet visit, dental care — this determines quality of life in later years.
Method: AAFP/AAHA table: 15 human years in year one, +9 in year two, then +4 per year.
These equivalences are statistical benchmarks drawn from published veterinary tables. Every animal ages at its own pace, depending on genetics, diet and care. This calculator is neither a diagnosis nor veterinary advice.
Frequently asked questions
My cat is 10 years old, what is the human age?
Approximately 56 human years. He enters the "mature to senior" category: this is the age when annual blood work becomes truly useful, especially to detect chronic kidney disease and hyperthyroidism, two common conditions in aging cats and very silent at first.
At what age is a cat a senior?
AAFP recommendations place the senior stage around 11 years, and old age beyond 15 years. Many cats live well past 18 years with adapted care.
Does cat size change the calculation?
No. This is a notable difference from dogs: the reference feline table does not vary by weight. Weight remains obviously important for health — but not for age conversion.
Does an indoor cat age differently?
The conversion is the same, but the actual life expectancy differs markedly: cats living exclusively indoors live on average much longer, essentially because they are protected from traffic accidents, fights and infectious diseases spread between cats.
And how is their health?
Age is just a number. Six questions about weight, diet and what you observe daily, and you get a health score out of 100 with concrete actions.
🩺 Do the pre-health checkFree, no account required, instant result.
Other calculators
These equivalences are statistical benchmarks drawn from published veterinary tables. Every animal ages at its own pace, depending on genetics, diet and care. This calculator is neither a diagnosis nor veterinary advice.