03818 -- U.S. ZIP code Municipality (1990): CONWAY, New Hampshire All ZIPs for this municipality (1990): 03818 Population (2000): 3280 Housing Units (2000): 1954 Land area (2000): 87.147144 sq. miles (225.710056 sq. km) Water area (2000): 0.354461 sq. miles (0.918051 sq. km) Total area (2000): 87.501605 sq. miles (226.628107 sq. km) Located within: New Hampshire (NH) Location: 43.966958 N, 71.158925 W