A generalized hydraulic calculation technique is presented that requires, as input, only the raw rheological data for the fluid and the values of the relevant hydraulic parameters. The method utilizes a powerful new rheological model called the Rational Polynomial model, which is capable of accurately representing the rheogram of virtually any time-independent fluid. Predictions of the new method are compared with published experimental data gathered from large-scale flow loops. The tested cases include laminar and turbulent flow for a variety of drilling fluids in both pipes and concentric annuli.