Transformers are one of the most costly, critical and major electrical components of the electric power system. Operation and stability of the electric power system mainly depend on the working of the transformer. Short-circuit forces can damage the transformer and accurate calculation of such forces is crucial for the transformer designers. Miscalculation can result in the non-optimal design. There are many different analytical methods for the calculation of the electromagnetic forces. However, these analytical methods do not consider the main factors of the transformer such as material properties of the winding and core, and complexity of the geometry. The numerical method like finite element method takes these factors into account. In this study, the 2-dimensional model is developed to calculate the short-circuit forces acting on the different parts of a 12-pulse converter transformer.