In researches on ducted wind turbines, in order to consider the effects of the duct, the solution process is dependent on parameters which arise from experimental tests or computational fluid dynamics. In the present study, our goal is to present a method for considering the effects of the duct and hub on the wind turbine enclosed in a duct without needing to costly experimental tests or time-consuming numerical simulations. For this purpose, the potential flow method which requires only lift and drag coefficients as input parameters is used. The surface vorticity method and the lifting line theory based on the Biot-Savart law are implemented as a numerical method to analyze the performance of the ducted horizontal axis wind turbine. The proposed method is programmed in the MATLAB software. The validation is carried out with experimental result of the DONQI horizontal axis wind turbine. The results are in good agreement with experimental data in the literature. The output power of the ducted wind turbine is compared to the same bare wind turbine to show the effect of the duct on the performance of the wind turbine. The power curve is illustrated that the ducted wind turbine produces more power than an unducted wind turbine in the same condition.