How many adults in the US? The latest completed U.S. population estimates show that about 269.8 million residents were age 18 or older as of July 1, 2025. The figure comes from the latest national age-based population estimates and places adults at nearly four-fifths of the country’s total population.
The United States had an estimated 341.8 million residents at that point. About 72 million were younger than 18, leaving approximately 269.8 million people in the adult population.
The latest available figures are especially useful because population totals change every year. The Census Bureau’s current national age data cover the population through July 1, 2025. A newer completed national estimate for people age 18 and older is scheduled for release in December 2026.
How Many Adults Are in the United States?
The latest official estimate puts the number of U.S. residents age 18 and older at approximately 269,763,509.
That number represents residents rather than a count limited to U.S. citizens. The age-based population measure includes people living in the United States who meet the age requirement.
The calculation also fits the broader national population figures. The total U.S. population reached 341,784,857 on July 1, 2025. The population under age 18 stood at 72,021,348.
Subtracting the under-18 population from the total produces the adult population:
341,784,857 − 72,021,348 = 269,763,509
That means roughly 269.8 million people in the United States were adults under the age-18 definition used for the population estimate.
For everyday use, rounding the number to 270 million provides an easy way to describe the size of the adult population. However, the more precise estimate is useful when comparing population statistics.
What Percentage of the U.S. Population Is Adult?
Adults represented approximately 78.9% of the U.S. population in 2025.
The under-18 population accounted for about 21.1%.
This means that close to eight out of every 10 people living in the United States were at least 18 years old.
The difference becomes clearer when the population is viewed as a simple ratio:
| Population group | Estimated population |
|---|---|
| Total U.S. population | 341,784,857 |
| Under age 18 | 72,021,348 |
| Age 18 and older | 269,763,509 |
| Adult share | About 78.9% |
| Under-18 share | About 21.1% |
These numbers show why the adult population is such a large part of the country’s overall demographic picture.
They also provide a straightforward answer for people searching for the current size of the U.S. adult population.
Why July 1, 2025 Is the Latest Completed Reference Point
Although the current year is 2026, the latest completed national age-18-and-over estimate covers July 1, 2025.
Population estimates require data collection, processing and demographic calculations. The Census Bureau releases different population products on different schedules.
The current Census schedule lists the next national and state population estimate for people age 18 and older for December 2026, using July 1, 2026 data.
As a result, a 2026 number should not be presented as an official completed age-18-and-over estimate before that release.
The 2025 figure remains the latest completed number available for this specific population category.
That distinction is important when searching online. Some population websites may show projections or calculations for 2026. Those numbers are different from a completed official estimate.
How the Adult Population Is Distributed by Age
The adult population covers a wide range of ages. Looking only at the overall total does not show how many people belong to different adult age groups.
The latest estimates divide the national population into several broad categories.
As of July 1, 2025, the estimated populations were:
- Ages 18–24: 31,936,859
- Ages 25–44: 91,885,062
- Ages 45–64: 81,324,500
- Age 65 and older: 64,617,088
Together, those groups total 269,763,509 residents.
The numbers show that adults ages 25 through 44 form the largest broad adult age group.
People ages 45 through 64 make up the next-largest group, followed by residents age 65 and older. Adults ages 18 through 24 represent the smallest of these four broad categories.
This breakdown gives a clearer picture of the nearly 270 million adults living in the country.
How Many Young Adults Are in the U.S.?
The United States had an estimated 31.9 million residents ages 18 through 24 in 2025.
This group represents adults who have recently reached the age of 18 through those in their early twenties.
The 18-to-24 population increased from 31,271,950 in 2020 to 31,936,859 in 2025. That was an increase of 664,909 people, or about 2.1%.
The change was modest compared with the growth seen in some other adult age groups.
Even so, the numbers demonstrate that young adults account for a significant portion of the national population.
How Many U.S. Adults Are Ages 25 to 44?
Adults between ages 25 and 44 represented the largest broad adult age group in the latest Census estimates.
The group included 91,885,062 people on July 1, 2025.
That was an increase of more than 5 million from the 2020 figure of 86,789,265.
The increase amounted to about 5.9% over the period.
This age range alone accounts for more than 90 million U.S. residents. Its size makes it an important part of the country’s overall adult population.
When combined with adults ages 18 through 24, the population younger than 45 but at least 18 totaled more than 123 million people.
How Many Adults Are Ages 45 to 64?
The latest estimate counted 81,324,500 people ages 45 through 64.
That represented a decline from the 2020 estimate of 84,004,580.
The group decreased by approximately 2.68 million people, representing a change of about 3.2%.
The decline in this age category occurred even as the overall U.S. population increased between 2020 and 2025.
Population changes do not affect every age group in the same way. Some groups can grow while others become smaller because people continuously move from one age category to another.
How Many Older Adults Are in the U.S.?
The United States had approximately 64.6 million residents age 65 and older in 2025.
The exact estimate for this age group was 64,617,088.
That represented a substantial increase from the 2020 estimate of 55,628,091.
The number of people age 65 and older increased by approximately 9 million between 2020 and 2025. That was a 16.2% increase.
As a result, older adults make up a significant portion of the country’s total adult population.
The 65-and-older group alone represented nearly one-quarter of all U.S. adults in 2025.
How Has the Number of Adults Changed Since 2020?
The overall U.S. population grew between 2020 and 2025, but the changes varied sharply by age.
The total population increased from 331,516,113 in 2020 to 341,784,857 in 2025.
That was an increase of more than 10.2 million residents.
The adult population also increased during that period. At the same time, the population younger than 18 decreased.
The under-18 population fell from 73,822,227 in 2020 to 72,021,348 in 2025.
That represents a decline of about 1.8 million people.
Meanwhile, several adult age groups grew. The 25-to-44 population increased by more than 5 million, while the 65-and-older population increased by almost 9 million.
These changes contributed to a larger adult share of the country’s population.
U.S. Adult Population at a Glance
The latest figures can be summarized in a few key numbers.
Total population: 341,784,857
Adults age 18 and older: 269,763,509
Population under 18: 72,021,348
Adult share of population: About 78.9%
Under-18 share: About 21.1%
Ages 18–24: 31,936,859
Ages 25–44: 91,885,062
Ages 45–64: 81,324,500
Age 65 and older: 64,617,088
The figures all refer to the same July 1, 2025 population estimate, making them directly comparable.
Does the Adult Population Include Everyone Age 18 and Older?
For this population measure, yes.
The Census Bureau publishes a specific national estimate for residents age 18 years and older. That definition separates the adult population from residents under 18.
The age cutoff matters because different demographic statistics sometimes use different age ranges.
For example, a statistic focused on the labor force may use an age threshold that differs from a population statistic. A study of voting eligibility may also use a different population definition.
Therefore, the figure of approximately 269.8 million should specifically be understood as the estimated U.S. resident population age 18 and older.
It should not automatically be treated as the number of eligible voters, workers or U.S. citizens.
Why the Total Adult Number Matters
The size of the adult population provides an important measure of the country’s demographic structure.
Nearly 270 million adults means that the overwhelming majority of U.S. residents fall into the 18-and-older category.
The figure also helps put other population statistics into perspective.
When researchers examine age-related changes, they can compare younger adults with middle-aged and older adults. The 2025 estimates show clear differences between these groups.
Adults ages 25 to 44 numbered nearly 91.9 million, while the 65-and-older population exceeded 64.6 million.
Those numbers show that the adult population contains several very large age groups rather than being concentrated in one particular stage of life.
How Many Adults in the US Will There Be in 2026?
There is not yet a completed official national age-18-and-over estimate for July 1, 2026.
The Census Bureau’s published release schedule identifies December 2026 as the planned release date for national and state population estimates for people age 18 and older based on July 1, 2026 data.
That means a definitive 2026 adult population figure should wait for the official release.
Using an estimate as though it were a completed Census figure would blur the difference between projected and finalized population data.
For readers looking for the most reliable current number, the July 1, 2025 figure remains the appropriate reference point.
The Current Answer to How Many Adults in the US
The latest completed population data show that approximately 269.8 million people age 18 and older lived in the United States as of July 1, 2025.
That figure represents about 78.9% of the country’s 341.8 million residents.
The adult population included nearly 32 million people ages 18 to 24, almost 91.9 million ages 25 to 44, more than 81.3 million ages 45 to 64, and about 64.6 million age 65 and older.
The figures also show how America’s age structure has changed since 2020. The population ages 25 to 44 and the population age 65 and older both increased, while the under-18 and 45-to-64 groups became smaller.
As of September 10, 2026, the latest completed national estimate remains tied to July 1, 2025. A newer official age-18-and-over estimate is scheduled for December 2026.
Do you think the latest U.S. adult population figure is higher or lower than you expected? Share your thoughts in the comments and check back for the next official population update.