The standard 12-lead ECG is often criticized for its lack of right sided and posterior leads. In contrast, the Body Surface Potential Map (BSPM) can employ over 200 leads to capture information from the entire surface of the torso. However, recording a large number of leads in routine clinical practice is impractical. This reality has led to the development of reduced lead sets, where a small number of leads are recorded and a mathematical transformation is used to derive the additional leads. In this study, we have developed a web based ECG viewer for transforming the 12-lead ECG into a BSPM. The resulting BSPM can then be explored using elaborate BSPM tools. This system was tested by transforming 20 12-lead aECG files into 192 lead BSPMs (Lux format). This was performed using transformation coefficients developed from an existing set of 192 lead BSPMs. The average transformation time on a PC (3GHz CPU, 3GB RAM) was 1.35 seconds. This tool presents more information than would be available with the 12-lead ECG. It has the potential to outperform current methods used to display ST elevation (24-lead view) and could therefore improve the recognition and diagnosis of myocardial ischemia.