What are the biggest generations in the US by population?

According to population projections from the US Census Bureau, millennials (born 1981-1996) make up the largest population group in the US in 2023, followed by baby boomers (1946-1964), Gen Z (1997-2012), and Gen X (1965-1980), respectively. 

Projections from a separate February 2020 US Census Bureau report show that from now until 2060, the US population is expected to grow by an average of 1.8 million people per year. International migration will be the main contributor to this growth in the coming decades as it overtakes natural increase—with the number of deaths rising faster than the number of births.

Here, we further break down the US population by generation and year, based on the national census report.

How big is the Gen Z population in the US?

Young people under the age of 25 make up about 40% of the world population, according to UN projections. But young people under 25 are just 31.1% of the total US population, and Gen Zers, ages 18 to 25, make up about one-third of this group.

Gen Z is incredibly diverse, with the percentage of minority Gen Z adults is the highest among all generations—and even bigger when looking at the entire Gen Z population. Including those under 18 in this cohort, nearly half of Gen Zers (49.8%) are non-white.

Not only is Gen Z an example of diversity—a leading indicator of how the US population is changing—but a champion of diversity, too, in their workplace, schools, and with the brands they associate with. Despite  growing up with unrelenting uncertainty and constant access to digital media, this group is demanding change to societal issues, including racial equity and climate change.

How big is the millennial population in the US?

In 2022, millennials made up the largest segment, accounting for 21.8% of the US population.

Millennials have experienced successive economic setbacks throughout their adult lives. Among the hurdles: employment and income pressure resulting from the Great Recession, soaring student-loan costs, stagnant wages, rising medical and housing costs, the COVID-19 pandemic, and, most recently, inflation.

While some studies have characterized millennials as more educated and employed than the generations that precede them, they’ve accumulated less household wealth, based on data from the Federal Reserve. This group is more likely to be paying off debt (primarily student loan debt), compared to their older cohorts, and in greater amounts, too. It may also be the reason why some millennials are delaying marriage and starting families at a later age—and even increasingly foregoing marriage and children altogether, which will shift population shares for the incoming Gen Alpha (2010-2024).

This may be why they are behind in homeownership, at a rate of 56.0%—11 percentage points lower than the national average. Nearly two-thirds of millennials find cities unaffordable, according to a survey by financial services firm Legal & General, and continue to put homeownership on the back burner.

How big is the Gen X population in the US?

The US Gen X population made up 19.3% of US residents, or 65.1 million individuals, in 2022. While Gen Xers were originally labeled as the “slacker” generation, their resilience through three recessions in the duration of their working career proves otherwise.

Although many Gen Xers are approaching mid-career and the peak of their earning power, they are sandwiched between financial booms and busts, as well as swings between social values across generations.

Gen Xers came of age with the rise of the tech economy, followed by the dot-com bust in the early 2000s and the financial crisis of 2008. They’ve spent a considerable amount of their working life in the longest economic expansion on record, only to see the pandemic bring back the shock, recovery, and risks of inflation—and now, Russia’s war against Ukraine.

How big is the baby boomer population in the US?

Baby boomers were the largest living adult population until 2019. According to the US Census Bureau, US boomers have remained the second-largest population group in 2022, comprised of 69.6 million people ages 58 to 76.  

The boomer generation is a mighty force powering American society and the economy. In comparison to their proportion in the overall population, boomers have oversized representation as S&P 500 CEOs, chief justices, and state governors.

Similar to Gen X, boomers have above-average incomes; yet their greater share of household wealth, Social Security allowances, an unmatched level of mortgage-free homeownership, and a detachment from a rocky job market—with many of them retired—leaves them positioned to survive financial blows. 

However, elevated inflation, volatility of retirement accounts, and rising medical costs may continue to chip away at the ability to maneuver financially, particularly for those on fixed incomes, as 70% of surveyed boomers expect to support themselves with Social Security when they retire.