The paper discusses the impact of Power MOSFETs (PMs) Capacitance-Voltage (C-V) characteristics on switching losses in Power Converters (PCs). A fast and robustly convergent numerical technique is adopted to analyze the sensitivity of PMs power losses with respect to their C-Vshapes. Such technique helps both in identifying desirable specifications for PMs design, and in achieving appropriate selection of PMs for PCs energy&reliability aware design. The results presented in this paper, concerning loss analysis and experimental verification for a 85V to 170V@0.5A dc-dc boost converter, highlight the PMs CVcurves impact and the valuable support of the proposed technique in PMs and PCs design.