U.S. Population by Age: Children and Older Adults
Published September 15, 2026 · StatsGalore
The U.S. median age reached 39.4 years in 2025, according to a Census Bureau analysis. QuickFacts reports that people under age 18 accounted for 21.1% of the population and people age 65 and older accounted for 18.9% in its current population-estimate figures. [1] [2]
The numbers
| Measure | Figure | Reference | Source |
|---|---|---|---|
| Total population | 341,784,857 | July 1, 2025, Vintage 2025 | [1] [2] |
| Under age 5 | 5.4% | 2025 population estimates | [1] [2] |
| Under age 18 | 21.1% | 2025 population estimates | [1] [2] |
| Age 65 and older | 18.9% | 2025 population estimates | [1] [2] |
| Median age | 39.4 years | 2025 | [1] [2] |
| Median age | 35.6 years | 2001 comparison in Census analysis | [1] [2] |
Median age is the midpoint
A median age of 39.4 means half the population is younger and half is older under the estimate. It is not life expectancy and it is not the age people are expected to reach.
The median can rise because the age distribution changes. It does not mean every person became older by the difference between two published medians, and it should not be interpreted as a direct measure of health.
[1] [2]Some age groups overlap
Children under age 5 are included among those under age 18. Adding the two shares would double-count the younger children. For a complete population breakdown, use age categories that do not overlap.
The under-18 and 65-and-older groups are separate. Their shares can be compared to understand the relative scale of children and older adults, but the remaining population should be defined explicitly before being labeled working age.
[1] [2]Population estimates have vintages
Census population estimates are revised as new information becomes available. A vintage is a consistent set of estimates for a series of dates. Historical values from different vintages can differ even when they refer to the same year.
The total population in this table is identified as Vintage 2025. For a detailed trend calculation, use a consistent vintage wherever possible instead of combining numbers copied from releases issued at different times.
[1] [2]What national age figures leave out
A national median hides substantial geographic variation. A community with many students can have a different age profile from a retirement destination even while both are part of the same country.
Age structure also does not reveal the needs or circumstances of any particular resident. These figures describe the composition of a population, while questions about employment, health, caregiving, or housing require additional measures.
[1] [2]Sources & notes
Sources: Census QuickFacts Vintage 2025 figures and the Census Bureau's April 2026 age-and-sex analysis. Age categories overlap where stated. The 2001 median is a historical comparison reported in that analysis.
Source review: 2026-09-15. Article publication and underlying data dates are separate. How we use statistics · Suggest a correction