Disclosed are a memory device that performs offset calibration and a method of operating the memory device. The memory device includes an input/output pad configured to receive data from a device external, an on-die termination (ODT) circuit connected to the input/output pad, a plurality of receivers connected to the ODT circuit and configured to receive the data from the input/output pad, an offset calibration circuit configured to perform an offset calibration operation on data output from the plurality of receivers and output an offset correction, a first switch configured to provide a first voltage to the plurality of receivers, and a second switch configured to provide a second voltage to the plurality of receivers. During the offset calibration operation, the plurality of receivers receive a third voltage in response to the ODT circuit being enabled and the first voltage through the first switch.