The defect chemistry of (La_0.8Ca_0.2)_0.95FeO_3±δ is analyzed using the La-Ca-Fe-O quaternary thermodynamic database. The quantitative Brouwer diagrams for LCF are developed in different temperatures and oxygen partial pressure. The detailed analysis of the charge disproportionation behavior and the electronic conductivity is carried out with the compound energy formalism model by applying the CALPHAD approach. The electronic conductivities are compared with the existing experimental measurements. The fundamental thermodynamic and kinetic analysis has been carried out to understand the factors affecting the experimental data and the thermodynamic database accuracy.