The performance of various hierarchized basis sets has been assessed by extrapolating the correlation energy to the estimated one-electron complete basis set limit. New hierarchical numbers are obtained which are found to lie close to previously reported ones for the Dunning correlation-consistent basis. Universal hierarchical numbers are also suggested, with correlation extrapolations showing a significantly better performance than when based on traditional protocols. It is observed that the accuracy of the extrapolation is enhanced when the underlying plot approaches linearity. (C) 2015 Elsevier B.V. All rights reserved.