Steady-state analysis of soft-switching converters is discussed in this paper. Finding the steady-state solution of soft-switching converters by means of start-up transient simulation may involve onerous computations and convergence failure, because of the mix of fast and slow natural frequencies determined respectively by the presence of soft-switching Lr-Cr cells elements and bulky L-C filter elements. The numerical method proposed in this paper shows high reliability and fast convergence, thanks to the adoption of an interval analysis based technique for the detection of commutations and of a compensation theorem based technique for the analysis of commutations. Some examples of steady-state analysis of two dc-dc converters, an inverter and a power factor corrector are presented to highlight the good performances of the simulation algorithm.