In cellular wireless networks where the signal attenuation is proportional to a power of the distance, evidence so far shows that cell splitting provides linear area spectral efficiency gain as the density of nodes increases. However, the investigation on cell-splitting has focused mostly on the throughput gain, while little attention has been given to the total transmit power needed for achieving such gain. In this letter, we provide the expression for the minimum transmit power that guarantees linear area spectral efficiency gain while performing cell-splitting. Then we use this expression for the power in order to show that, whenever the path-loss exponent is greater than two, increasing the cell density yields a reduction of the total transmit power in the network while achieving linear gain in terms of area spectral efficiency.