Frankfort, IN -- U.S. city in Indiana Population (2000): 16662 Housing Units (2000): 6682 Land area (2000): 5.141720 sq. miles (13.316993 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 5.141720 sq. miles (13.316993 sq. km) FIPS code: 25324 Located within: Indiana (IN), FIPS 18 Location: 40.282182 N, 86.511466 W ZIP Codes (1990): Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Frankfort, IN Frankfort