This paper presents comprehensive ripple analyses for generalised multiphase switch-tapped-inductor boost converters. Input and output currents and voltage ripple expressions are derived for converters with any number, N, of phases. It is shown that due to interleaving, highest possible total input- and output-side ripple changes very little as the number of phases and hence total power increases. An N-phase converter's performance is shown to be much better than that for single-phase converter. The ripple analyses developed for multiphase switch-tapped-inductor boost converters are very general in nature. They are therefore applicable to several other variants of tapped-inductor converters that have been reported in the literature. This suggests that a unified approach to evaluate interleaved tapped-inductor converters performance exists.