with thanks to www.CatFanciers.com Converting Cat Years to People Years There are many tables for converting between cat years and human years. Many of them use a very simple calculation (e.g. 1 cat year equals 7 human years). This is inaccurate because: The average life for a house cat (excluding accidents, in particular, car runovers) is about 1/5th that of a person, not 1/7th.  A cat has a relatively short childhood. A cat with an expected lifespan of 15 years would be sexually and physically mature within 18 months. A man with an expected lifespan of 75 years would have the equivalent maturity at 15-18 years of age. For this reason, an accurate mapping of cat years to human years needs to consider factors other than chronological lifespan. This is shown in the following table: Calendar Years In A Cat's Lifespan Equivalent Human Longevity 0 - Birth 0 - Birth 1 - Sexual Maturity 15 - Sexual Maturity 2 - Physical Maturity 20 - Physical Maturity 3 - Adulthood 25 - Adulthood 4 30 5 35 6 40 7 - Middle Age 45 - Middle Age 8 50 9 54 10 58 11 - Senior Age 62 - Senior Age 12 66 13 70 14 - Geriatric Age 74 - Geriatric Age 15 78 16 82 17 - Venerable Age 86 - Venerable Age 18 90 19 94 20 - Remarkable Age 98 - Remarkable Age The oldest confirmed recorded age for a cat is 34 years. The oldest confirmed recorded age for a human is 122 years. Factors affecting lifespan and health It is not unusual for a house cat to reach 15 years or even 20 years of age, whereas an intact tomcat living in the wild has a life expectancy of about 3 years. Some general factors that affect lifespan are: Gender. Female cats tend to live slightly longer than male cats. Neutering. Neutered cats tend to live longer than intact cats.There is evidence that neutered cats, especially neutered tomcats, benefit from a reduced exposure to infectious diseases (they stay closer to home). Diet. The three major natural causes of death in cats are kidney and/or liver failure, cancer and infectious diseases. Suitable foods (including special reduced protein cat food for older cats) can significantly delay organ problems and may also reduce cancers. Living Conditions. A claimed and protected environment will result in a healthier cat, which can be expected to live longer. For this reason, house cats typically live longer than barn cats or feral cats. Medical Attention. Cats should be vaccinated against the common feline diseases. Infectious disease is one of the three main natural causes of cat death. Like people, cats periodically require medical treatment for illness or injury, especially as they get older. Individual Characteristics. Just as some people are born with a strong constitution, so are some cats. Consequently, while one can talk about the expected lifespan of a cat based on the above factors, individual cats will vary somewhat from this.