A quick automatic method for computing aerodynamic performance of ducted propellers is presented. The thrust- and power-coefficients and propulsive efficiency are calculated and plotted against the advance ratio. The representative blade section is investigated. It is found that the most suitable section is one at 75% radius as the same as nonducted cases. Thrust coefficient is predicted satisfactorily. But propulsive efficiency is overestimated; the difference seems to be “blower efficiency” defined in a previous paper.