Median Age in King County, WA
ACS 2024 5-Year Estimates
37.4 years
Rank #2,694/3,222 · #31 in WA
16th
King 37.4 years
WA 38.3 years -2.3%
US 38.9 years -3.9%
Median Age Trend
Rankings →Percentile Rank Over Time
Year-over-Year Age Change
National Distribution
How King County's median age of 37.4 years compares to all 3,222 U.S. counties. Values range from 21.4 years to 86.2 years.
Distribution of Median Age Across All Counties
Ranking Context
Counties ranked closest to King County for median age.
Nearby Rankings
Full ranking →| #2,691 | Neshoba County, MS | 37.4 years |
| #2,692 | Madison County, NE | 37.4 years |
| #2,693 | Knox County, TN | 37.4 years |
| #2,694 | King County, WA | 37.4 years |
| #2,695 | Mississippi County, AR | 37.3 years |
| #2,696 | San Diego County, CA | 37.3 years |
| #2,697 | Arapahoe County, CO | 37.3 years |
About Median Age
King County, Washington has a median age of 37.4 years, ranking #2,694 of 3,222 counties nationwide — 3.9% below the national value of 38.9 years. Within Washington, it ranks #31 of 39. This places it in the 16th percentile nationally.
The median age of the total population. Source: U.S. Census Bureau, American Community Survey 2024 5-Year Estimates. All values are estimates derived from survey samples and are subject to margin of error. For more information, see our methodology.