According to the United States Census Bureau, the borough had a total area of 4.243 square miles (10.989 km2), including 3.999 square miles (10.358 km2) of land and 0.244 square miles (0.632 km2) of water (5.75%) [REF].
Carlstadt is bordered on the south by East Rutherford in Bergen County, Secaucus and North Bergen in Hudson County, on the north by Wood-Ridge and Moonachie (Bergen) to the east by Ridgefield and South Hackensack (Bergen), and to the northwest by Wallington (Bergen) [REF].