We have developed a first-principles based generalized model for assessing the propensity of thermodynamically stable as well as metastable inorganic materials toward electrochemical stabilization, passivation, or corrosion in aqueous media. This formalism allows us to evaluate the relative Gibb’s free energy of arbitrary materials with respect to Pourbaix stable species at any pH, voltage, temperature, and concentration of ions. This formalism is useful for general corrosion management as well as for optimizing operating conditions for aqueous-media-based applications like photocatalysis. An open-source web application based on the formalism is available at https://materialsproject.org which can be used to determine the electrochemical behavior of more than 80,000 materials available through the Materials Project database. Future work is focused on integrating this formalism with the Point Defect Model for studying time-dependent corrosion and passivation behavior of materials.