Static and dynamic light scattering experiments were performed to characterize the copolymer of tetrafluoroethylene (TFE) and perfluoromethyl vinyl ether (PMVE). Solvents of perfluoro-2-butyltetrahydrofuran (FC-75) and Flutec PP11 (PP11) were used to dissolve the TFE-PMVE copolymer. By taking advantage of the solvent properties of FC-75 and PP11, homogeneous TFE-PMVE copolymer solutions were specially prepared in a FC-75/PP11 mixed solvent. Such prepared solutions could provide a strong enough scattered intensity for light scattering studies. The molecular weight, molecular weight distribution, chain dimensions, and conformation were determined for the TFE-PMVE copolymer in the FC-75/PP11 mixed solvent. A combination of viscosity and molecular weight measurements enabled the calculation of the k value in the relation of eta(o) = k (M-w)(3.4) and thus the prediction of the molecular weight of a given TFE-PMVE copolymer with the same composition by using only the simpler and more readily available rheological measurements.