Abstract: In order to minimize the axial thrust exerted on centrifugal impellers, seal rings and balance holes are usually employed on hubs. Based on pressure distribution inside a rotating fluid body and empirical formula for axial thrust evaluation, we formulated an approach to determine leakage quantitatively and calculate axial thrust. We also demonstrated that seal rings and balance holes must be used simultaneously, only in this way can the axial thrust be reduced. The research will be beneficial for engineers in balance mechanics design practice of centrifugal impellers.