A method is proposed by which the interfacial energy, gamma(SL), of polycrystalline solid oxides (Al2O3, ZrO2) in contact with liquid metals and certain binary liquid alloys can be calculated from the values of the surface energy of the oxides, gamma(SV), and the liquid metals or liquid alloys, gamma(LV), respectively. According to this method, the interfacial energy depends on the geometric mean of surface interactions, (gamma(SV) gamma(LV))1/2, the molar volumes, V, of the solid and liquid phases, and a parameter, K, which depends on the geometric details of the oxide surface defined by the ion sites in the oxide as well as the stoichiometry of the elements in the oxide and is given by the equation, gamma(SL) = (K(V(metal)/V(oxide) + 1)2/3 (gamma(SV) gamma(LV))1/2 The method was verified using interfacial energy data obtained by measurements of the contact angle, 0, formed between the oxides and the liquid metals and liquid alloys with the sessile drop technique. A good agreement was observed between the calculated and the experimentally estimated values of gamma(SL) at the melting point of the metals and alloys.