Current sharing scheme based on input power and/or the power efficiency for a power stage with multiple phases and/or paralleled modules is described. According to the scheme, duty cycles of different phases/modules may be adaptively adjusted until the minimum input power and/or the maximum power efficiency is achieved. For certain input voltages, the minimum input power exists at the minimum total input current. Thus, input power and/or the input current may be used as an indicator of the maximized power efficiency of the power stage and hence be used to track the optimal current sharing ratio among the multiple phases/modules.