An accurate dead-time adjustment method for phase-shifted full bridge (PSFB) converter is presented. This method allows the dead-time of converters to be optimised to meet zero voltage switching condition. The optimum dead-time range can be predicted with high accuracy for any type of power semiconductor switch, including gallium nitride high-electron-mobility transistor, so that a practical design for a PSFB converter can be realised. The validity of the proposed dead-time optimisation method was verified by experimental results with a 600 W prototype.