Past and recent x-ray and absorption data on chromonic liquid crystals are analyzed in a consistent manner to reveal both the cross-sectional areas and stacking free energy changes for a number of systems. Two tentative conclusions result from this study. First, the locations of the charged groups on the dye molecule determine the number of molecules in the cross-section of the aggregate. Second, among systems with the same aggregate structure, the higher the stacking free energy change as measured in dilute solutions, the lower the concentration at which a room temperature liquid crystal phase forms at higher concentrations.