The alpha decay half lives and other characteristics of 190 even–even super heavy elements in the range 100 ⩽ Z ⩽ 120 has been determined within the Coulomb and Proximity Potential Model (CPPM). The computed Q values and log 10 ( T 1 / 2 ) values plotted against neutron number of parent nuclei were studied and it was found that neutron shell closures in the super heavy region occur at N = 162 and N = 184 . The alpha decay half lives for parent nuclei with atomic number Z = 106 onwards were compared with experimental data and are found to be in good agreement with each other. A semi-empirical formula for alpha decay half lives has been formulated by making least squares fit to the available experimental data. The new semi-empirical formula was used for calculating half lives of isotopes of nuclei in the chosen range 100 ⩽ Z ⩽ 120 . These results when compared with the corresponding experimental half life values and the values calculated using GLDM and Viola–Seaborg systematics showed good agreement.