In this paper, a power density analysis is presented for 7nm FinFET technology node based on both shorted-gate (SG) and independentgate (IG) standard cells operating in multiple supply voltage regimes. A Liberty-formatted standard cell library is constructed by selecting the appropriate number of fins for the pull-up and pull-down networks of each logic cell. Next, each cell is characterized by doing SPICE simulations to calculate the propagation delays and output transition times as a function of input transition times and load capacitance values. Finally, the power density of 7nm FinFET technology node is analyzed and compared with the 45 nm CMOS technology node for different circuits. Experimental result shows that the power density of each 7nm FinFET circuit is 3-20 times larger than that of 45nm CMOS circuit under the spacer-defined technology. Experimental result also shows that the back-gate signal enables a better control of power consumption for independentgate FinFETs.