The Pt/MgO (100) interface electronic properties have been analyzed with first principles density functional theory plus nonequilibrium greenes function (NEGF) framework. We analysed n-type schottky barrier hight (SBH) of metal-insulator (Pt/MgO) interface for various biase voltage using two probe model. The applied bias voltage +0.5 V for left and right electrode of supercell, we found large n-SBH is 3.12 eV due to strong interface dipoles. Similarly, in the case of bias voltage -0.5 V for left and +0.5 V for right electrode the n-SBH is lower by 1.91 V. These large SBH values are useful in electronic applications. © 2020 Author(s).