About 722,000 people alive today are aged 100 or older, according to United Nations population projections for 2024. That sounds like a lot, but it represents a tiny fraction of the global population. In the United States, centenarians account for roughly 2 out of every 10,000 people. Reaching 100 is still exceptionally rare, though it’s becoming less so with each passing decade.
The Numbers in the U.S.
The U.S. Census Bureau counted 80,139 centenarians living in the country in 2020. That was a 50% jump from 53,364 in 2010, making centenarians one of the fastest-growing age groups in the population. Still, the national rate sits at just 2.42 per 10,000 people.
Pew Research Center projects the U.S. centenarian population will quadruple over the next 30 years. Globally, the picture is even more dramatic: the world is expected to have 3.7 million centenarians by 2050, roughly an eightfold increase from recent counts. Better healthcare, declining infant mortality, and improvements in managing chronic disease are all pushing more people into extreme old age.
Where Centenarians Are Most Common
Japan leads the world with 106 centenarians per 100,000 people. That rate is partly driven by diet, universal healthcare, and strong social networks, but also by a population structure that skews older than most countries. Guadeloupe follows at 92 per 100,000, then Uruguay at 84, Puerto Rico at 78, and Hong Kong at 72. These figures, drawn from UN data, show that centenarian hotspots aren’t limited to wealthy nations or a single region. They span the Caribbean, South America, and East Asia.
What Determines Who Gets There
Genetics accounts for about 25% of the variation in human lifespan. That’s a meaningful chunk, but it means roughly three-quarters of the equation comes down to environment and behavior. For most of your life, through your 70s or so, lifestyle choices matter more than your DNA. Not smoking, staying physically active, eating well, and limiting alcohol are the factors that separate people who reach a healthy old age from those who don’t.
After 80, genetics starts to play a larger role. Researchers believe certain gene variants help protect against age-related diseases or improve cellular repair, allowing some people to keep functioning well into their 90s and beyond. If you have close relatives who lived past 95 or 100, your own odds improve. But no single “longevity gene” has been identified, and having long-lived relatives doesn’t guarantee anything without the lifestyle to match.
What Life at 100 Actually Looks Like
Reaching 100 doesn’t necessarily mean thriving at 100. Research from the Georgia Centenarian Study found that only 20 to 25% of centenarians are both living in the community (not in a care facility) and cognitively intact. At least 50% have some form of cognitive impairment, and 60 to 70% have significant physical disability. Some are completely dependent on caregivers for daily activities.
That said, the centenarians who do remain independent tend to share certain traits: they stayed socially connected, maintained physical activity into their later years, and often had a sense of purpose or routine. These aren’t guarantees, but they appear consistently in longevity research across different cultures.
What Centenarians Eventually Die From
The causes of death at 100 look somewhat different from those at younger ages. Heart disease remains the leading cause, followed by Alzheimer’s disease and stroke. Cancer, which dominates mortality statistics for people in their 50s through 70s, drops to fourth place among centenarians. Influenza and pneumonia round out the top five, reflecting how vulnerable extremely old immune systems are to infections that younger people fight off easily.
The shift away from cancer is notable. People who survive to 100 appear to have some biological resistance to tumor growth, or at least to the aggressive forms of cancer that kill at younger ages. Their biggest vulnerabilities are cardiovascular and neurological, the systems most affected by simple wear over time.
Beyond 110: Supercentenarians
If reaching 100 is rare, reaching 110 is nearly unheard of. The Gerontology Research Group, which tracks and validates extreme age claims worldwide, currently lists 214 living supercentenarians. That’s 214 people out of 8 billion. The validation process is strict, requiring birth certificates, census records, and other documentation, so the true number may be slightly higher in countries with less complete record-keeping. But even generous estimates put the global supercentenarian population in the low hundreds. The jump from 100 to 110 represents one of the steepest mortality curves in human biology.