Map of Key West
As of the censusGR2 of 2000, there were 25,478 people, 11,016 households, and 5,463 families residing in the city. The population density was 1,653.3/km² (4,285.0/mi²). There were 13,306 housing units at an average density of 863.4/km² (2,237.9/mi²).
There were 11,016 households out of which 19.9% had children under the age of 18 living with them, 37.7% were married couples living together, 8.2% had a female householder with no husband present, and 50.4% were non-families. 31.4% of all households were made up of individuals and 8.1% had someone living alone who was 65 years of age or older. The average household size was 2.23 and the average family size was 2.84.
In the city the population was spread out with 16.0% under the age of 18, 8.4% from 18 to 24, 37.1% from 25 to 44, 26.7% from 45 to 64, and 11.7% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 122.3 males. For every 100 females age 18 and over, there were 126.0 males.
The median income for a household in the city was $43,021, and the median income for a family was $50,895. Males had a median income of $30,967 versus $25,407 for females. The per capita income for the city was $26,316. About 5.8% of families and 10.2% of the population were below the poverty line, including 11.5% of those under age 18 and 11.3% of those age 65 or over.
The ancestries most reported in 2000 were English (12.4%), German (12.2%), Irish (11.3%), Italian (6.8%), United States (6.0%), and French (3.6%).