The Z/(Z+1) approximation for the calculation of Auger electron energies is examined, and, in its present form, it is shown to be inappropriate for calculations of free atoms. A modified formula, using removal energies of free ions of charge Z+1, is as shown to be generally superior to the traditional formula, and is usually comparable in accuracy with Hartree-Fock calculations for Auger transitions of the order of 1 keV or less. For cases involving two final-state holes in different shells transition energies of low-energy Auger transitions can be estimated to about 1 eV.