Abstract: A system and method of use is provided for using electrochemical impedance spectroscopy to determine the corrosion rates of coupled metals. Two dissimilar metals are coupled together and exposed to a saltwater electrolyte in an electrochemical cell. A variable frequency current is passed through the cell and collected at the coupled metals. The impedance and phase angle of the collected current data are plotted verses frequency. The plotted data are compared to and analogized to a known plot for physical electric circuits. When a matching plot and circuit are found, the corrosion rate data associated with the matched plot are used to determine the corrosion rates of the coupled metals.