A theory based on calculation of phase diagrams in the binary systems was developed that describes Gibbs-Thomson effect. In this model effect of both interfacial energy and interface confinement (Laplace-Young pressure) are included in energy shift of alloys and phases. By using the CALPHAD model, interfacial energy of Cu4Ti precipitates in Cu-Ti system was obtained which shows better consistency with experimental results of Gibbs-Thomson effect of 10-20 nm radius precipitates.