64440 -- U.S. ZIP code Municipality (1990): DE KALB, Missouri All ZIPs for this municipality (1990): 64440 Population (2000): 744 Housing Units (2000): 291 Land area (2000): 37.079447 sq. miles (96.035323 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 37.079447 sq. miles (96.035323 sq. km) Located within: Missouri (MO) Location: 39.585185 N, 94.909573 W