Nanopores have found increasing numbers of applications in basic science research and biotechnological devices. The favorable physical and chemical properties of solid state nanopores makes them attractive for many of these applications. However, the geometry and surface properties of such nanopores is often variable and must be characterized for each experiment. Such characterization typically takes place before or after the experiment. We have developed an approach to characterize the geometry and surface characteristics of nanopores using electrochemical impedance spectroscopy (EIS).