We scrutinized the conventional practice of measuring an electrolyte stability window. It is shown that misleading values might be generated by this practice. Thus, we recommend that to obtain a real stability window, the working electrode material should simulate the electrodes used in a real device. Further, in applications that have a high-surface-area electrode, a new quantification of a stability window is proposed. The electrochemical stability values of various nonaqueous electrolytes that are derived this way should reflect the actual operation limits of these electrolytes in real-life devices.