Stainless steels, especially ferritic ones, are used in heat-resistant devices, home appliances, construction materials due to their high corrosion resistance, high and low temperature availability, mechanical strength and long-time durability. In this study, it was aimed to identify the Johnson-Cook (JC) parameters of the AISI 430 ferritic stainless steel depending on the gage length variation. After preparing tensile samples with seven different gage lengths (0.5, 1, 2, 5, 10, 20 and 50 mm), the samples were subjected to tensile tests at the same deformation speed (2 mm/s). Here, the variation of the yield stress depending on the strain rate was investigated because the deformation speed was kept constant and the gage length was changed. The tensile tests at different strain rates were conducted on the same setup. The materials were also subjected to the tensile tests at different temperatures on reference strain rate to perceive the change of the yield stresses at elevated temperatures. As a result of these tests, the JC parameters of the material were determined. Finally, by using these parameters, the tensile test simulations of the material were performed in the finite element simulation package. When the obtained experimental and numerical data were compared, it was determined that there was a deviation of 3.17% between them and the validity of the JC parameters of the material was proved.