Mobile, Alabama is 5.6 times larger than Manhattan (NYC borough).
Area: 59 km2 calculated
Manhattan is the most densely populated of the five boroughs of New York City. The borough is coterminous with New York County, an original county of the U.S. state of New York. Wikipedia
Area: 329 km2 calculated
Mobile is the county seat of Mobile County, Alabama. The population within the city limits was 195,111 as of the 2010 United States Census, making it the third most populous city in the U.S. Wikipedia