Cat to Human Age Calculator
Convert your cat's age to an equivalent human age using the American Association of Feline Practitioners (AAFP) life-stage framework. The AAFP guidelines establish that the first cat year equals approximately 15 human years, the second cat year adds 9 more (reaching 24 human years), and each subsequent year adds approximately 4 human years. This non-linear model reflects the rapid development cats undergo in early life. Enter your cat's age in years to see the human-equivalent age and AAFP life stage.
Cat-to-human age conversion formula (AAFP)
Year 1 = 15 human years
Year 2 = 24 human years (9 more)
Each year from year 3 onward = +4 human years
Human age = 24 + (cat age - 2) x 4, for cats older than 2 years
Based on the American Association of Feline Practitioners (AAFP) and American Animal Hospital Association (AAHA) Feline Life Stage Guidelines. The AAFP life stages guide preventive care schedules at each phase of a cat's life.
AAFP feline life stages
- Kitten: 0-6 months (human equivalent: 0-10 years)
- Junior: 7 months to 2 years (human equivalent: 10-24 years)
- Prime: 3-6 years (human equivalent: 28-40 years)
- Mature: 7-10 years (human equivalent: 44-56 years)
- Senior: 11-14 years (human equivalent: 60-72 years)
- Geriatric: 15+ years (human equivalent: 76+ years)
Cat to human age calculator: frequently asked questions
How is a cat's age converted to human years?
The American Association of Feline Practitioners (AAFP) life-stage guidelines provide a standard reference. Cats age rapidly in early life: year 1 equals approximately 15 human years, year 2 equals approximately 24 human years. After that, each additional cat year equals roughly 4 human years.
What are the AAFP cat life stages?
The AAFP defines: Kitten (0-6 months), Junior (7 months to 2 years), Prime (3-6 years), Mature (7-10 years), Senior (11-14 years), and Geriatric (15+ years). These stages align with equivalent human life phases and guide preventive care recommendations.
Why is early cat life equivalent to so many human years?
Cats reach sexual maturity around 6-9 months and are fully grown by 2 years. This rapid early development is why 1 cat year is considered equivalent to about 15 human years, compared to the slower maturation rate of humans.
What changes at the mature and senior life stages?
From age 7 (mature), cats benefit from biannual veterinary visits, blood panels to catch early kidney or thyroid disease, dental cleanings, and weight monitoring. The AAFP recommends age-appropriate care beginning at the mature stage.
How old can cats live?
Indoor cats typically live 12-18 years. Well-cared-for cats regularly live into their 20s. The oldest documented cat on record (Creme Puff, USA) lived to 38 years. Indoor living, preventive care, and healthy nutrition are the main factors in longevity.
Official sources
- American Association of Feline Practitioners (AAFP): AAFP Feline Life Stage Guidelines.
- AAHA/AAFP: 2021 AAHA/AAFP Feline Life Stage Guidelines.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.