The rapid escalation of user traffic and service innovation has made the deployment of small cell base stations essential for eventually decreasing energy consumption in future generation wireless network. An energy efficient small cell zooming strategy is proposed using weighted majority cooperative game for two-tier fifth generation (5G) mobile network. The proposed strategy is referred as ‘5G-ZOOM-Game’. Small cells ‘zoom in’ and ‘zoom out’ dynamically according to the proposed ‘5G-ZOOM-Game’ algorithm. Different frequency sets are assigned to small cells based on adjacency for reducing interference. In the proposed approach femtocells are used as small cells. The proposed algorithm is applied between two adjacent femtocells. Out of two adjacent femtocells, higher majority femtocell is selected based on weighted majority game; this femtocell zooms its coverage area. The utility function of the proposed approach is defined to connect maximum possible number of mobile devices by increasing the higher majority femtocell’s coverage area. Higher majority femtocell is chosen based on the load and minimum distance between mobile device and femtocell base station. Proposed 5G-ZOOM-Game network reduces ~ 35% of power consumption and increases signal-to-interference-plus-noise-ratio (SINR) and spectral efficiency by ~ 30% and ~ 60% respectively than the existing approaches.