Geography of Boston, Massachusetts
Boston has an area of 89.63 sq mi—48.4 sq mi (54%) of land and 41.2 sq mi (46%) of water. Logan International Airport has determined the official elevation of the city to be 19 feet above sea level. At 330 feet above sea level, Bellevue Hill is the highest point in Boston; the city's lowest point is at sea level. Boston Harbor, which is an arm of Massachusetts Bay and, by extension, the Atlantic Ocean, provides access to the city.
The Greater Boston metropolitan area encircles Boston. The area is bordered as follows: the town of Winthrop and the Boston Harbor Islands border it on the east; Revere, Chelsea, and Everett border it on the northeast; Somerville and Cambridge border it on the north; Watertown borders it on the northwest; Newton and Brookline border it on the west; Dedham and small portions of Needham and Canton border it on the southwest; Milton and Quincy border it on the southeast. Allston-Brighton, Fenway-Kenmore, and Back Bay are geographically isolated from Watertown and the majority of Cambridge by the Charles River, while the mass of Boston is geographically separated from its own Charlestown neighborhood. The Neponset River forms the boundary between the southern neighborhoods of Boston, Quincy, and Milton. East Boston is geographically isolated from Downtown, the North End, and the Seaport, while Chelsea Creek and Boston Harbor divide East Boston from Chelsea and Everett.
Population of Boston
Boston was projected to have 691,531 people living in 266,724 households in 2020, representing a 12% growth in population compared to 2010. With an over 500,000-person population, the city is the most densely populated state capital and the third-most densely populated large metropolis in the United States. During business hours, approximately 1.2 million individuals may be within the boundaries of Boston, and up to 2 million during special events. The hundreds of thousands of suburban residents who travel to the city for work, education, health care, and special events are responsible for this population fluctuation.
The age breakdown of the city's residents was as follows: 21.9% were aged 19 or younger, 14.3% were aged 20 to 24, 33.2% were aged 25 to 44, 20.4% were aged 45 to 64, and 10.1% were aged 65 or older. Thirty-eight years was the mean age. The male-to-female ratio was 92.0 to 100. Males outnumbered females aged 18 and older by 89.9 to 100. Twenty-four percent of the 252,699 households contained children under the age of eighteen; twenty-five percent were married couples cohabiting; sixteen percent were headed by a woman without a spouse; and non-families comprised the remaining 54 percent. A total of 37.1% of households consisted of individuals, with 9.0% having a member aged 65 or older residing alone. The average family size was 3.08, and the average household size was 2.26.