The energy loss of heavy ions is due to collisions with electrons and with nuclei. The first process is essentially determined by the ionic charge, which in turn depends on the ratio of the velocities of the most loosely bound electron within the ion, and of the ion. The former velocity is calculated from the Thomas-Fermi model while the ratio of the two velocities is adjusted to empirical data. The nuclear contribution to the stopping cross section is calculated by the known classical method. Though approximations could not be avoided, the procedure lends itself to the systematization of experimental data on intermediate and heavy ions.