Joints of circular hollow section (CHS) structures are the most critical portion of such structures. Estimating fatigue life using the structural stress approach requires peak hot-spot stress in a CHS joint in conjunction with the corresponding S–N curve. Available parametric equations for determining stress concentration factors (SCF) in the CHS KT-joints under out-of-plane bending (OPB) moments typically estimate SCF only at the saddle point. However, this assumption neglects potential variations in SCF along the weld toe. For joints under a multiplanar load (combined load), the location of peak hot-spot stress (HSS) varies, depending on the relative magnitude and directions of planar load components. Superposition of stresses is used to determine peak HSS in such situations; however, the equations determining SCF at saddle point only are not sufficient. This study investigates CHS KT-joint subjected to OPB load on all brace members and proposes an empirical model for determining SCF at 24 points along the weld toe. 1858 KT-joints were simulated through ANSYS to generate data for training artificial neural networks. An empirical model was developed for rapid calculation of SCF in KT-joints under OPB. The proposed model was validated with detailed finite element results, and the maximum difference was less than 5%. Experimental validation of the developed model is a future target.