Plainwell, MI -- U.S. city in Michigan Population (2000): 3933 Housing Units (2000): 1593 Land area (2000): 2.072266 sq. miles (5.367145 sq. km) Water area (2000): 0.086861 sq. miles (0.224970 sq. km) Total area (2000): 2.159127 sq. miles (5.592115 sq. km) FIPS code: 64740 Located within: Michigan (MI), FIPS 26 Location: 42.443349 N, 85.642683 W ZIP Codes (1990): 49080 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Plainwell, MI Plainwell