King of Prussia, Pennsylvania, United States [CDP]; population was 18,406 in 1990; housing units was 8,376 in 1990; location is 40°6'N 75°23'W; land area is 8.40 square miles (5,374 acres); water area is 0.07 square miles (45 acres); FIPS code is 39736 [SourceCBP]