Stepped channels are effective for dissipating the energy of supercritical flows that occur at steep channels, dams, weirs, and drop structures. As stepped channel flows are characterized as aerated flows, it is important to estimate the energyh ead of the aerated flow for a hydraulic design of the stepped channel. Recently, the authors proposed a method for estimating an energy head of skimming flow Ew by using a clear water depth. But, an energy head of air-water flow Eres in stepped channels has not been estimated. In this paper, a method for estimating the energy head of air-water flows Eres in stepped channels is presented. Also, the relationship between Ew and Eres is discussed under given discharge, channel slope, and step height. The experimental investigation reveals that the magnitude of Eres is nearly equal to Ew. Further, the relation between the actual velocity of an aerated flow and the velocity obtained according to the clear water depth in stepped channels is shown.