Recent work has shown that mechanical cues from the extracellular environment can influence cell division. However, it is unclear whether dividing cells are directly sensing external forces or are responding to changes in cell shape. Furthermore, there is little understanding of how to infer the stresses acting on individual cells due to global forces without invasive experimental manipulation. We have developed a mathematical model in which cellular stresses can be inferred using only knowledge of the position of cell junctions, relieving the need to disruptively measure forces experimentally. This modelling has been used in conjunction with experiments, in which Xenopus laevis embryonic cells were subjected to a tensile stretch, to unveil how mechanical cues are controlling cell division.