A membrane electrode assembly is subjected to carbon corrosion accelerated stress tests (ASTs) involving the application of square-wave voltage cycles with different upper limits to measure the resulting loss in the mass of the carbon support at the cathode catalyst layer (CL) and the associated degradation in performance. Carbon loss is determined from the amount of CO2 evolved during degradation, while the performance loss is measured from the reduction in the cell voltage at 1.5 A cm−2 relative to the performance obtained in its beginning-of-life state. A kinetic model for carbon corrosion describing the rate of evolution of CO2 is shown to accurately predict the carbon loss measured during the various carbon corrosion ASTs in this study. A plot of the performance losses from the various carbon corrosion ASTs versus the corresponding carbon losses reveals that all the data demonstrate consistent degradation regardless of the AST conditions, and these result can be fitted with an exponential function termed the ‘fingerprint’ expression. By combining the carbon corrosion model and fingerprint expression, both the carbon loss and performance loss of a cathode CL during a carbon corrosion AST can be accurately predicted based only on knowledge of the waveform of the input voltage.