The deformation limits of sheet metals, which are determined with localizationand fracture, represent an important parameter for the analyses ofsheet-metal forming processes. The forming limits of sheet metal are represented by a forming limit diagram (FLD), which shows the various deformation states. For an experimental determination of a FLD extensive and expensive tests are necessary. An alternative method for determining the forming limit curve (FLC) is an analysis performed using numerical simulations. This paper introduces a method for determining the forming limit curve for the whole range of the FLD for sheet metal. A simulation of the Marciniak test with the finite element method (FEM) was performed for hot-galvanized steel using the ABAQUS program. The criterion for determining the FLD with a numerical simulation is presented. Finally, the numerically obtained forming limit curve is compared with an experimental curve.