 According to the United States Census Bureau, Browns Mills had a total area of 5.612 square miles (14.534 km2), including 5.367 square miles (13.900 km2) of land and 0.245 square miles (0.634 km2) of water (4.36%).As of the 2000 United States Census there were 11,257 people, 3,946 households, and 2,939 families living in the CDP.The population density was 799.0/km2 (2,070.8/mi2).