We began by defining the features required for organic stable radical active species to be viable candidates for redox flow batteries (Fig. ). For commercial viability, RFBs need to achieve a high charge density and high reversibility (i.e., longevity) at low cost. A benefit of organic active species is their ability to be incorporated as pendant groups into large macromolecules. Polymer-based RFBs allow cheaper size-exclusion membranes to be used and provide an additional lever for tuning the solubility of active materials. Pendant groups must therefore have a precisely tuned redox potential to take full advantage of the solvent's electrochemical stability window, and a highly stable, long-lived radical center to avoid reactions that might reduce the battery's capacity over time. Finding a single redox-active species that can perform both the oxidation and reduction reactions simplifies the battery design and reduces capacity fade through membrane cross-over. Radical groups must also be synthetically accessible. In this study, we estimate standard redox potentials with adiabatic (i.e., geometry-optimized) ionization potentials and electron affinities obtained from implicitly solvated DFT thermochemistry including vibrational zero-point energy. Further, we estimate radical stability using a recently developed metric that incorporates both thermodynamic and kinetic stabilization of the radical center using 3D structural features and electron spin density obtained via DFT. Highly-delocalized and sterically protected radicals are prioritized by this approach. Synthesizability is considered by constraining the synthetic accessibility score (SAscore) of the closed-shell R-H molecule to be less than 4.0 and by ensuring that the R-H bond is relatively weak, with a homolytic bond dissociation enthalpy (BDE) of 60-80 kcal/mol. While many thermal and photochemical synthetic protocols exist to form radicals from a closed-shell parent organic compound (e.g., deoxygenation, dehalogenation, etc.), this BDE constraint limits our candidates to those that could be generated by a facile and selective latestage H-atom abstraction.