Oak Ridge National Laboratory’s Solid-state batteries (SSBs) have the potential to be significant next-generation technologies for high-energy and high-power-density rechargeable battery applications. It is crucial to identify the metrics that an emerging battery technology should fulfill to achieve parity with conventional lithium-ion batteries, primarily in terms of energy density. However, limited approaches exist today to assess and extrapolate the impact of battery designs and choices of cell components on the cell-level energy density of an SSB. The Solid-State Battery Performance Analyzer and Calculator (SolidPAC) is an interactive experimental tool kit that enables SSB design for user-specified application requirements. The tool kit is flexible, enabling the battery community to quantify the effects of materials chemistry and fractions, electrode thicknesses and loadings and electron flows on cell energy density and costs and to use reverse-engineering concepts to correlate the cell energy density output to materials and cell design inputs.