The significance in electrochemistry of the term ‘polarization’ is carefully explained. Several diverse effects contribute to the overall polarization and the magnitudes of the corresponding overvoltages may be calculated via equations that are presented. An informative graphical method of presenting data on the evolution of the individual overvoltages during voltammetry is described and exemplified. The diagram may be constructed from experimental data or as part of a predictive exercise using either digital simulation or convolutive modelling. Four examples of these polarization inventory diagrams are presented. Among the features that may be factored into the diagrams are various voltammetric protocols, electrode reactions of any degree of reversibility, arbitrary transfer coefficient, diffusion coefficient diversity, varied cell geometries, transport by diffusion and/or migration, first-order homogeneous reactions, uncompensated resistance, and multi-layered electrolyte solutions.