Abstract. An increasing, degree of rich and dynamic content and abundant links are making Web pages visually cluttered. This paper presents a numerical tool to evaluate the screen complexity of a Web page using four critical measurements: size complexity, local density, grouping, and alignment. In the empirical study, we first translate the real screens from four first pages on Ebay auction web sites to serve as model screens that contain the structure of complexity without content. We subsequently compare the complexity values calculated from the model screens with the viewers' judgment from the real screens. The resemblance between the results indicates that the tool is useful.