The method proposed in this paper is based on an analytical rating method which has been developed some years ago by the author (see AGMA paper 88FTM6). The calculation is based on the determination of the maximum of pressure between the mating teeth which is made by using a specific criteria for worm gears. The method can be used to verify the load capability of a worm gear but also to design a new gear covering several types of tooth profile. Calculations are provided as examples and comparisons have been made with results obtained by the initial analytical method@ and by standardized methods (AGMA@ BS).