Based on per capita income, one of the more reliable measures of affluence, Shoreline ranks 91st of 522 areas in the state of Washington to be ranked.
The name "Shoreline" first came to be applied to this stretch of unincorporated King County in 1944, when it was given to the school district. As the city stretches from "Shore to Shore" (Puget Sound to Lake Washington) and "Line to Line" (Seattle city limit to Snohomish County Line), so was it rumored to have been named. This statement is not entirely true, since Shoreline city limits do not, in actuality, go from shore to shore, since Shoreline's eastern border stops around 25 AVE NE in most areas of the city, bordering the city of Lake Forest Park, which does border Lake Washington. Fifty-one years later, on August 31, 1995, Shoreline was officially incorporated as a code city and adopted the council-manager form of government. (See City government in the state of Washington.)
According to the United States Census Bureau, the city has a total area of 11.7 square miles (30.3 km²), of which, 11.7 square miles (30.2 km²) of it is land and 0.04 square miles (0.1 km²) of it (0.17%) is water.
There are 330 acres (1.3 km²) of park land in Shoreline, divided among 25 parks. Shoreview and Boeing Creek Parks, which abut Shoreline Community College, contain a ravine through which flows Boeing Creek on its way to Hidden Lake and Puget Sound.
There were 20,716 households out of which 30.6% had children under the age of 18 living with them, 51.2% were married couples living together, 10.0% had a female householder with no husband present, and 34.9% were non-families. 26.4% of all households were made up of individuals and 9.1% had someone living alone who was 65 years of age or older. The average household size was 2.50 and the average family size was 3.03.
In the city the population was spread out with 22.5% under the age of 18, 7.7% from 18 to 24, 30.4% from 25 to 44, 24.8% from 45 to 64, and 14.5% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 93.2 males. For every 100 females age 18 and over, there were 90.1 males.
The median income for a household in the city was $51,658, and the median income for a family was $61,450. Males had a median income of $40,955 versus $33,165 for females. The per capita income for the city was $24,959. About 4.4% of families and 6.9% of the population were below the poverty line, including 6.1% of those under age 18 and 7.3% of those age 65 or over.