Population & Households Quick Statistics
2015 population estimate for Seattle: 662,400
2010 Census estimates for Seattle:
- 2010 population count: 608,660
- Population in households: 583,735
- Number of households: 283,510
- Average household size: 2.06
- Average family size: 2.87
- Population in group quarters: 24,925
- 2010 population count: The 2010 Census counted Seattle’s population at 608,660. Seattle has the largest population of cities in King County and the broader Seattle-Tacoma-Bellevue Metro Area. Seattle is the 23rd most populous city in the U.S.
- Population growth by decade: From 2000 to 2010, Seattle’s population grew by 8 percent: slightly slower than in the 1990s, but a healthy rate of growth for a major U.S. city.
- Household size: In 2010, the average number of people per household in Seattle was 2.06. Average household size has been declining nationally for many decades. The increase in one-person households is a key reason average household size has continued to go down in Seattle.
- Age: In 2010, nearly three-quarters of Seattle residents were adults between 18 and 64 years of age, with an especially high concentration of young adults (age 25 to 34). The highest rates of population growth between 2000 and 2010 were for children under 5 and adults age 55 to 64.
- Annual population growth since 2010: Seattle’s population has continued to grow. The state Office of Financial Management (OFM) estimates that Seattle’s population was 616,500 as of 2012.
- Forecast: As of 2010, about 31% of King County’s 1.9 million residents lived in Seattle. OFM forecasts that the county’s population will grow from about 1.9 million persons in 2010 to about 2.4 million persons in 2040
Census 2010 Citywide Reports
Key Data Sources
U.S. Census Bureau Data
Two Census Bureau programs provide the most commonly used sources of demographic data at a community and neighborhood level:
- The decennial census is done every 10 years to count the population and gather basic information about population demographics, households, and housing units. (Topics include age, sex, race, Hispanic ethnicity, household composition, owner / renter status, and group quarters populations.)
- The American Community Survey is a continuous survey that produces estimates on a broad set of population, social, economic, and housing characteristics. The American Community Survey has replaced the long form that used to be part of the decennial Census.
The Washington State Office of Financial Management
The Office of Financial Management's (OFM’s) Forecasting Division produces official population estimates for cities and towns and produces population projections to assist with growth management. OFM is also the Census Bureau’s official partner for disseminating demographic data in Washington state.
The Puget Sound Regional Council
PSRC provides estimates and forecasts at a range of geographic scales as part of the work to support planning in the central Puget Sound region.
Where to Go From Here
- Dig deeper into the data we’ve compiled from the decennial Census and ACS, and get important tips on how to use the data and avoid common pitfalls
- See our geographic files and maps to check out how characteristics vary by neighborhood, get reference maps, and download associated information
- See our Neighborhoods page for similar information by different neighborhoods
- Find links to related information and resources including the Census Bureau’s American Factfinder data portal, population estimates and forecasts OFM and the Puget Sound Regional Council, growth targets in Seattle’s Comprehensive Plan, and demographic data from Seattle Public Schools and the Public Health department serving Seattle and King County