This method is for determining the loss on ignition (LOI) of fresh and regenerated catalysts or catalyst supports of various commercial shapes and sizes, including fines, using an ignition temperature of 900°C. The method is quantitative down to 0.1 mass-%. The method is not water specific and other volatile components such as chlorine or fluorine are also included in the LOI. The LOI of spent catalyst and spent catalyst fines containing carbon or coke cannot be determined by this method. Mass gains are possible with catalysts that contain reduced metals.