Manhattan has an estimated population of 1.63 million people, all living in an area of just 23 square miles. This gives Manhattan a population density of 70,826 people per square mile. Manhattan is the most densely populated of the five NYC boroughs and also the most densely populated county in the United States. It is more dense than any city in the country and one of the most densely populated areas on earth.
On weekdays, the number of commuters pushes the Manhattan population to more than 3.9 million, or 170,000 people per square mile.
Manhattan is the smallest borough in terms of land area and the third-largest in terms of population behind Brooklyn and Queens. Between 2000 and 2030, the population of Manhattan is expected to grow by 289,000 people. The school-age population is expected to increase, compared to an expected decline in New York City as a whole, by the elderly population is projected to grow by 58%.