What are the biggest generations in the US by population?

According to data from the US Census Bureau, millennials (born 1981-1996) made up the largest population group in the US in 2021, 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?

Gen Z is expected to make up 20.2% of the US population by 2022, or fully 68.2 million tweens, teens, and young adults ages 9 to 24. As the third-largest cohort, Gen Z is the most racially, ethnically, and sexually diverse generation in history

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?

By 2022, millennials are expected to still make up the largest segment, accounting for 21.8% of the US population.

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).

How big is the Gen X population in the US?

The US Gen X population is expected to make 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.

Economic setbacks haven’t stopped Gen Xers from holding household incomes above the US average. Many are still recovering from the Great Recession, even before COVID-19 doubled down on financial hardships, which makes it difficult for them to keep up with responsibilities, including mortgages, car loan payments, and tuition for their kids. 

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 will remain the second-largest population group in 2022, comprised of 69.6 million people ages 58 to 76.  

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.