Worldwide, more people who are age 100 and above (centenarians) are alive today than ever before, and the number of those older than 110 (supercentenarians) is also expanding rapidly.

For 99% of the time humans have lived on Earth, life expectancy at birth was under 20 years. Now the population and lifespan of the world's oldest people are continually increasing due to improved healthcare and lifestyles, along with a growing world population.

The oldest person ever whose age was verified (age 122) was Jeanne Calment (1875 -1997).  She was born in Arles, France, to a well-to-do family, and led a relaxed life pursuing hobbies including tennis, cycling, swimming, and piano. Ms. Calment's father lived to 93 and a brother lived to age 97.  She lived on her own until age 110 when she moved to a nursing home. Ms. Calment gained international fame in 1988 - the centenary of Vincent Van Gogh's visit to Arles.  She recalled meeting Van Gogh when she was age 14 and remembered him as "dirty, badly dressed, and disagreeable."

The oldest male and second oldest person ever (age 121) was Shigechiyo Izumi of Tokunoshima, Japan (1865 -1986).  Mr. Izumi does hold the record for the longest working career for a person --  spanning 98 years.  He began working with animals at a sugar mill in 1872 and retired as a sugarcane farmer in 1970 at age 105.  Mr. Izumi attributed his long life to "God, Buddha, and the Sun."  He stood only 4 feet 8 inches tall, and weighed 94 pounds.

The oldest American and third oldest person ever (age 119) was Sarah Knauss (1880 - 1999).  She was born in a small Pennsylvania coal-mining town.  Asked at age 115 if she enjoyed her long life, Knauss said, "I enjoy it because I have my health and I can do things." 

The oldest African-American and eighth oldest person ever (age 116) was Elizabeth Bolden who died in 2006.  She had seven children and at the time of her death had 40 grandchildren, 75 great-grandchildren, 150 2^nd great-grandchildren, 220 3^rd great-grandchildren, and 75 4^th great-grandchildren.

The oldest living woman and man today (both age 114) are Eugenie Blanchard of St. Barts in the French Caribbean and Walter Breuning of Montana, each born in 1896. The six oldest people currently living were all born in 1896.

There is conflicting evidence regarding which factors lead to longevity:

Diet? - The fifth oldest person ever Marie-Louise Meilleur was a vegetarian, but the third oldest person Sarah Knauss had a weakness for junk food.

Easy life? - The oldest person Jeanne Calment and the sixth oldest Maria Capovilla of Ecuador were wealthy and lived relaxed lives. However, the oldest American and the oldest African-American both grew up poor and worked hard.

How to live longer? Most experts agree that it is important above all to have an easygoing personality, while many also believe it is important to eat right, not to smoke, to exercise, and ... to be born female.

Possible difficulties in living to 100 include outliving friends, family, spouses, and even one's own children. In addition, it is likely that centenarians will exhaust their life's savings

How long will you live? For an educated guess, try the living to 100 life expectancy calculator.