🐈 Cat Age Calculator (Cat Years to Human Years)
Enter your cat's age to see it in human years and its life stage, using the standard veterinary conversion.
Human-age equivalent
36 human years
Life stage
Prime adult
Using the standard veterinary chart: a cat's first year ≈ 15 human years, the second year adds 9 (≈ 24), then about +4 human years per cat year after that. Indoor cats often live 15+ years. 🔒 In your browser.
How the cat age calculator (cat years to human years) works
Cats age fastest in their first two years. Following the veterinary chart (AAHA/AAFP), the first year is about 15 human years, the second year adds another 9 (≈ 24 in total), and every year after that adds roughly 4 human years. The tool applies this and shows the matching life stage, from kitten to senior.
This is the widely-used veterinary reference chart; individual cats vary with breed, lifestyle and health. Indoor cats commonly reach 15+ years — the equivalent of a human in their mid-seventies or beyond.
Frequently asked questions
How old is my cat in human years?
The first year counts as about 15 human years, the second brings the total to about 24, and each year after adds roughly 4. So a 5-year-old cat is about 24 + 3 × 4 = 36 human years.
How do cats age compared to humans?
Very fast at first — a 1-year-old cat is roughly a 15-year-old human, and a 2-year-old about 24 — then about 4 human years per cat year. This reflects rapid early development followed by steadier ageing.
What are the cat life stages?
Broadly: kitten (under 1), junior/young adult (1–6), mature (7–10), senior (11–14) and geriatric (15+). Knowing the stage helps tailor diet, activity and vet check-ups.
How long do cats live?
Indoor cats often live 13–17 years and many reach the late teens or older; outdoor cats typically less. That's equivalent to a human living well into their seventies or eighties.
Is a cat year the same as a dog year?
No — the curves differ. Both age fast early, but the per-year human-equivalent after age two is about 4 for cats, while for dogs it depends on size. Use the matching calculator for each.