To find the maximum stresses acting at certain point in an element, a transformation is required to find the new directions were all the stresses are normal to the surface of the element that is to say, shear stresses vanished. This new coordinates are the principal axes and the normal stresses are called principal stresses. Those types of transformations are difficult to visualize and thus understand. Therefore, three-dimensional visual aids that help visualize the response in a wider approach will be very beneficial. Stress Calculator is a Java-based utility that was created to serve in the educational process by modeling the infinitesimal part of an element under the action of the stress tensor. The results obtained will be used to study the more reliable failure theories also in a tridimensional output