How King County Compares

King County

37.4 years

Washington Average

37.4 years

Rank #31 of 39 in state

National

38.9 years

3.9% below

National Distribution

Where King County falls among all 3,222 U.S. counties for median age.

21.4 years 86.2 years

■ King County: 37.4 years

Ranking Context

Rank	County	Value
#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

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Median Age in King County, Washington

King County, Washington has a median age of 37.4 years, which ranks #2,694 of 3,222 out of 3,222 counties nationwide. This is 3.9% below the national value of 38.9 years.

Within Washington, King County ranks #31 of 39 out of 39 counties. This places it in the 16th percentile nationally.

The median age of the total population. All data comes from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates for 2024.

About this data

Source: U.S. Census Bureau, American Community Survey 5-Year Estimates (2024). All values are estimates derived from survey samples and are subject to margin of error. For more information, see our methodology.