Boston is the capital and most populous city in the Commonwealth of Massachusetts in the United States. The city serves as the cultural and financial center of the New England region of the Northeastern United States. It has an area of 48.4 sq mi (125 km
2) and a population of 675,647 as of the 2020 census, making it the third-largest city in the Northeast after New York City and Philadelphia. The larger Greater Boston metropolitan statistical area has a population of 4.9 million as of 2023, making it the largest in New England and the eleventh-largest in the country.