A rollable display device including a rollable display panel including a plurality of pixels each having an organic light emitting element, a panel driving circuit configured to drive the rollable display panel, a power supplying circuit configured to supply a high power voltage and a low power voltage to the rollable display panel, such that the organic light emitting element emits light based on the high power voltage and the low power voltage, and an ohmic drop compensation margin changing circuit configured to sense a degree that the rollable display panel is unrolled and change an ohmic drop compensation margin of the low power voltage to compensate ohmic drops based on the degree that the rollable display panel is unrolled.