Internet users can fail at several hurdles, e.g. issues related to trouble-free and selfexplanatory interaction. Not only users but also organizations are affected adversely by these difficulties. The purpose of this study is to enhance the limited repertoire of methods for quantifying web applications usability, which have remained unchanged for years. It first develops a model explaining the relationship between usability dimensions and success variables. Consecutively, the model’s hypotheses are empirically validated by conducting an experiment for testing Internet Banking applications. Results show positive usability effects of increased recognizability, real world metaphors, anticipating support, dominant designs and a higher degree of freedom through the undo button. For practitioners, this research offers a quantitative method for development and quality management projects. Its scientific contribution consists of adding a novel approach for usability measurement in the field of Usability Engineering. It provides findings about the relationship between usability dimensions and usability success factors which presents a basis for further research in this field.