This result is an estimate only. Check with your bank or the relevant authority before making decisions.
How it is calculated
At 1 year: 15 human years
At 2 years: 24 human years (the second year adds 9)
After 2 years: 24 + 4 × (cat age − 2)
Between 1 and 2 years the value rises steadily from 15 to 24
The life stage follows the 2021 AAHA/AAFP Feline Life Stage Guidelines. For dogs, use the dog age calculator.
Worked example
A 5-year-old cat:
24 + 4 × (5 − 2) = 36 human years
Life stage: young adult
A 12-year-old cat: 24 + 4 × 10 = 64 human years, in the senior stage.
Why your number may differ
The conversion is an average, not a measurement. Indoor and outdoor cats, different breeds and health conditions all age differently. Kittens under one year are not covered. This is not veterinary advice.
Frequently asked questions
How is a cat’s age converted to human years?
The AAHA and AAFP guideline counts the first year as 15 human years, the second year adds 9 more to reach 24, and each year after that adds about 4.
What are the cat life stages?
The 2021 AAHA/AAFP guidelines list kitten (up to 1 year), young adult (1–6 years), mature adult (7–10 years) and senior (10 years and over).
Is this exact?
No. It is a guide, and cats age at different rates depending on health, diet and genetics. Ask your vet about your cat’s health and check-ups.