The described embodiments relate to improving efficiency of a low-profile cooling fan. In one embodiment, an impeller of the cooling fan includes a shroud which covers a central portion of the impeller, thereby allowing a central inlet portion of the blades to have an increased fan blade height when compared to a cooling fan constrained by minimum part tolerances between the fan blades and a portion of the fan housing. In some embodiments, the impeller includes splitter blades that can improve performance of the low-profile cooling fan.