Science and industry are conducting intensive research into various ways of improving existing battery concepts or transferring new concepts into application. An essential step in this process is the development of materials and electrodes. However, evaluating the achieved performance parameters and comparing different studies at this level of technology with respect to practical applications is challenging, since laboratory scale usually involves the use of specific electrodes and cell concepts. We have developed a simple calculation tool (Ragone calculator) to estimate performance data at the full cell level based on electrochemical measurements on electrodes. The use of the Ragone calculator simplifies the comparison of different studies and provides a reasonable estimate of reported performance data. The extrapolation of results at battery level can also make a valuable contribution to assessing at an early stage whether a development is on target or in which direction it should be taken forward.