Expressions of partial molar enthalpies and enthalpies of mixing of binary systems are derived using the Wilson equation, according to basic thermodynamic principles. The partial molar enthalpies and mixing enthalpies of Sn-based binary alloys are calculated based on the Wilson equation’s interaction parameters, which were obtained by the method of nonlinear least-squares. Calculated values are statistically in agreement with experimental data reported in the literature. The results indicate that the method proposed in this work is reliable for predicting thermodynamic properties for Sn-based binary alloys.