The use of thin glass in construction promises a variety of potentials for a more sustainable use of resources. Innovative constructions can enable thin glass to become an important component of structural glass engineering. However, there is still a lack of in-depth knowledge and corresponding standards for a reliable and standardized use of thin glass. One particular challenge is the determination of the bending tensile stresses for building product standardization. Due to the low geometric stiffness, conventional test methods such as the four-point bending test can no longer be applied. Alternative test methods have already been developed and investigated. Thereby, an increased influence of Poisson´s Effect with decreasing thickness of the glass has been suspected. The test specimens deform far beyond the small deformation field and activating non-linear behavior which leads to a significant shift from unidirectional to a multidimensional stress situation. Rather, it leads to a considerable bending along the width of the specimen, depending on the aspect ratio, thickness and the extent of the curvature. This research investigates the influence of the geometric dimensions of a test specimen as well es the load magnitude on the stresses calculated by the linear elastic Euler–Bernoulli beam theory. For this purpose, an extensive parameter study is carried out by means of the finite element method. With more than 200 variants, the maximum stresses as well as their distribution over the width is compared. This leads to a more accurate understanding of the effect of lateral strain at large deformations and helps in the selection of geometry and a more realistic evaluation of ultimate stresses in thin glass.