64456 -- U.S. ZIP code Municipality (1990): GRANT CITY, Missouri All ZIPs for this municipality (1990): 64456 Population (2000): 1642 Housing Units (2000): 844 Land area (2000): 157.072302 sq. miles (406.815377 sq. km) Water area (2000): 0.088475 sq. miles (0.229149 sq. km) Total area (2000): 157.160777 sq. miles (407.044526 sq. km) Located within: Missouri (MO) Location: 40.496954 N, 94.389934 W