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Data and Reports

King County residents and elected officials depend on accurate data to conduct business and to make better decisions about county products and services. Staff of  Performance, Strategy and Budget (PSB) are dedicated to providing reports and analysis that standardize the data used within King County and promote good decision-making.

Our Services: 

The county demographer and other staff within PSB prepare annual and periodic reports and respond to requests about King County characteristics and trends. These reports draw on national and local sources, and they provide interpretive analysis of the application of these data sources within King County. These data reports, are described below. In addition, the demographer responds to hundreds of data requests each year from within and outside  King County government about population and housing characteristics, land use, and employment trends through the county.

For more demographic information, please contact:

Rebeccah Maskin
Demographic Planner

Performance, Strategy and Budget

(206) 263-0380

  Text for screen readers 2018 King County Quick Facts

Demographic Presentation A presentation to the King County Council describes recent demographic trends and the current ethnicity, language and income characteristics of King County residents.

Demographic Information:  In 2011 the US Census Bureau released population counts from the 2010 Census that confirm Washington State and King  County growth in recent years. In April 2010, the Census counted 1,931,249 people in King County. In the years since 2010, the Washington State Office of Financial Management (OFM) has published annual population estimates for Washington counties and cities. OFM's estimate of King County's 2018 population is 2,190,200.

In the years since the 2000 and 2010 decennial Censuses, the US Census Bureau has conducted a new survey of population characteristics called the American Community Survey (ACS). Tables of recent ACS data are available for   King County, summarizing demographic, economic, social and housing characteristics.

Demographic Resources: Find additional data from a variety of King County, Washington, and national resources:

  • iMap Interactive mapping tool for King County spatial data, from the King County GIS Center
  • Local Scape From the Assessor’s Office, select a city or draw a custom neighborhood on a map to find assessed value, sales, census and other data
  • Employment Data The Puget Sound Regional Council creates annual employment estimates for cities and census tracts
  • OFM Population Estimates The Washington Office of Financial Management creates the state’s official population and housing estimates and forecast
  • Census Data Through the decennial census and American Communities Survey, the Census Bureau provides population counts, demographics, and lots more data

King County Buildable Lands Report: In 1997, the Washington State legislature adopted the Buildable Lands amendment to the Growth Management Act, (RCW 36.70A.215). The amendment requires six   Washington counties and their cities to determine the amount of land suitable for urban development, and evaluate the capacity for growth, based upon measurement of five years of actual development activity.   King   County and the other five counties were required to report to the State by September 1, 2002 and every five years thereafter.

Archive: King County Annual Growth Report: The King County Annual Growth Report was launched in 1983 to document population and land development data for King  County, its cities, and its unincorporated areas.

2008 Annual
Growth Report

Note: The past years' King County Annual Growth Reports are available for viewing in Adobe Acrobat .pdf format. You will need to have a copy of Adobe Acrobat Reader installed on your computer to view the report files. You can download a free copy of the Acrobat Reader here or visit Adobe's site to get more information.

Archive: King County Benchmark Report:  In 1995, elected officials and citizens throughout the County helped develop a set of 45 indicators, which directly relate to the policies in our countywide Growth Management plans. Our Benchmark Report reviews how we are doing on each indicator, giving us a broad-brush picture of our quality of life. Through the Report we've tried to find objective ways to determine if our quality of life is getting better or worse at the community level.