A novel simplified EKV model base analog/RF CMOS design pre-SPICE tool is presented in this paper. Addition to facilitating the sizing process, this CAD tool can also optimize circuit characteristics. By having a web address, users can access it without installing any software. Usinga graphical and a numerical view, the designer can select degrees of freedom and observe the MOS circuit performance. Through the use of charts versus IC, the graphical view can show tradeoffs in circuit performance in real time. Charts can be displayed simultaneously in both linear and logarithmic scales. ICcrit, is also available and can be displayed on the charts. This tool is not limited to one process and it is possible to select different processes. A methodology for selecting optimum ICsis presented by this tool. It is illustrated through the study of linearity indices, AIP3 and IIP3, in one-stage and two-stage differential amplifiers.