1 definition found carlstadt - U.S. Gazetteer (1990) : Carlstadt, NJ (borough, FIPS 10480) Location: 40.82450 N, 74.06392 W Population (1990): 5510 (2449 housing units) Area: 10.2 sq km (land), 0.7 sq km (water) Zip code(s): 07072