We have addressed a critical knowledge gap regarding the accurate characterization of reactivity ratios and other rate coefficients for two-component equilibrium copolymerization reactions. We present a detailed analysis of multiple methods to characterize this class of copolymerization reactions and demonstrate their general precision and accuracy. We rectify mistakes present in two original publications that derive equilibrium copolymer equations, assert the consistency between disparate forms of copolymer equations, and identify where the assumptions used in their derivations are invalidated. Additionally, a practical population balance method is introduced for these systems. We make recommendations for the process of data fitting and show that through transiently setting homopropagation rate coefficients equal to unity, the number of fit parameters can be reduced with no loss of accuracy and enables others to be measured independently of copolymerization experiments. It is shown that linearized methods and other simplified models previously used in the literature are inaccurate, and we discourage their further use. As proof-ofconcept, we fit seven sets of equilibrium copolymerization data, giving chemically intuitive insights into copolymerization behaviors, and highlighting the utility of the methods evaluated herein. The analysis and tools presented in this work will enable the rapid, simple, and accurate evaluation of equilibrium copolymerization reactions toward the development of chemically recyclable polymers, circular materials, and advanced data-driven methods and predictions.