10504 -- U.S. ZIP code Municipality (1990): ARMONK, New York All ZIPs for this municipality (1990): 10504 Population (2000): 7185 Housing Units (2000): 2434 Land area (2000): 16.666829 sq. miles (43.166886 sq. km) Water area (2000): 0.245539 sq. miles (0.635944 sq. km) Total area (2000): 16.912368 sq. miles (43.802830 sq. km) Located within: New York (NY) Location: 41.129908 N, 73.703521 W