The paper focuses on determining the optimal set of link lengths for the 2R serial robot based on the ideal values for the distribution of the most relevant kinematic performance indices on an imposed reachable workspace. MathWorks MATLAB was used to numerically evaluate the distributions of the performance indices inside the imposed reachable workspace among multiple configurations for the two link lengths. A unitless term, \(k\) , was used to determine the link lengths of the structure and through iteration among the imposed workspace and among the values of \(k\) , an optimal solution is determined based on the formulation of the target function.