A user-friendly semi-empirical formula for the description of electron impact double ionization cross-sections of heavy Sc1+, Ti5+, Fe6+, Ni3+, Ga, Kr4+, Rb1+, Mo3+, Ag, Sb1+, In, Xe4+, Cs1+, Ba2+, Pr3+, Sm6+, W6+, Hg, Pb, Bi1+, and U targets for the incident electron energies from threshold to 106 eV is proposed. The formula contains both the direct and indirect components leading to double ionization. The parameters of the model are determined from the best fit to the available experimental cross-sections using a nonlinear least-squares fitting computer program. It was noticed that the formula represents the experimental data for a fairly wide range of atomic heavy species over a wide range of incident energies.