The invention concerns a method for determining several parameters of a seated person, comprising the following steps: subdividing the seat surface (4) into at least two sections, determining the barycenter position of the active weight in each section, and evaluating said parameters of said person based on said determined positions. The evaluation of said parameters can include the evaluation of the size and/or weight of said person, the evaluation of the position of the said person on said seat based on the distribution of the barycenter positions on the seat or the evaluation of the orientation of said person on said seat based on the longitudinal positions of the barycenters of the active weight in each section.