Aiken is located at 33°33'36" North, 81°43'9" West (33.560000, -81.719444).
According to the United States Census Bureau, the city has a total area of 16.19 mi2 (41.93 km2). 16.18 mi2 (41.90 km2) of it is land and 0.01 mi2 (0.04 km2) of it is covered by water. The total area is 0.09% water.
Aiken is located in the Eastern Standard Time (EST) timezone, GMT-05:00. It observes Daylight Saving Time (DST).