Disclosed is a memory device including a magnetic memory element. The memory device includes a memory cell array including a first region and a second region, the second region configured to store a value of a write voltage, the write voltage based on a value of a reference resistor for determining whether a programmed memory cell is in a parallel state or anti-parallel state, a voltage generator configured to generate a code value based on the value of the write voltage, and a write driver configured to drive a write current based on the code value, the write current being a current for storing data in the first region.