How long do cats live? With regular veterinary exams and routine care, most indoor cats live to their teens and many into their twenties. The oldest cat recorded lived to be 38 years old. Cats are often regarded: Kittens from birth to 6 months of age Teenagers/juniors from 7 months to 2 years Adults from 3 to 6 years Mature from 7 to 10 years Seniors from 11 to 14 years Geriatric from 15 years and up Of course, these stage vary with the individual and with overall health.