The actual effect of notches on fatigue strength of mechanical components is quantified by fatigue stress concentration factor Kf . This parameter is associated with the tolerance to short fatigue cracks departing from stress raisers with high stress gradient effects. At sharp notches, local yielding can occur around the notch roots, thus the short crack behavior should be modeled considering localized plastic strains. The Stress Gradient Method (SGM), based on Fracture Mechanics and short crack concepts, can be used to predict the Kf . For elongated notches that locally yielded, the SGM s solution should be modified to take into account the cyclic hardening of the material around notch roots. The prediction of Kf through SGM consists in using the material properties and the geometric characteristics of both the specimen and the notch to generate the distribution of plastic stress gradient factor (SGF), which is given by genSIF.exe, a software that calculates stress intensity factors by means of weight functions and the finite element method. Then, from the short fatigue crack concepts developed by El Haddad-Topper-Smith, a non-linear equation is proposed to compute the plastic Kf through an iterative approach which can be implemented and solved in MATLAB. The results predicted by SGM are compared with experimental Kf data.