Ideal gas thermodynamic properties for biphenyl have been calculated by statistical thermodynamics method on the basis of available experimental data and the results of recent high-level quantum mechanical calculations. More precise information about the potential barriers to internal rotation and the lowest vibrational frequencies made it possible to achieve the best agreement with calorimetric results in comparison with statistical calculations published earlier. The thermodynamic functions have been also estimated using molecular structure, vibrational frequencies, and potential barrier heights of biphenyl calculated by B3LYP/cc-pVTZ density functional method.