A novel method for calculating the thermodynamic properties of ternary oxides using borogermanates and germanosilicates as examples is proposed. Using regression coefficients obtained for germanates, borates and silicates, the heat capacity, formation enthalpy, entropy and Gibbs free energy of alkaline borogermanates and germanosilicates were calculated. The obtained enthalpy of formation values are in good agreement with experimental data. In the regression equation, the alkaline oxide thermodynamic potential coefficients were found to depend on the class of compound.