This study presents a method to calculate the stress on the different components of complex welded joints to calculate the welded seam.The method is applied to a complex welded joint on an Ishaped beam, welded and reinforced with plates, in an overlap joint.The proposed method is validated by the Finite Element Method.Results show differences lower than 5% between the proposed method and the Finite Element simulation, proving the applicability of the method to any complex welded joint.