<p>In this paper, the theoretical bearing capacity of deep foundations in soils has been studied parametrically by means of a numerical implementation of limit analysis. Both the drained and undrained conditions were considered, the effect of dilatancy was included approximately, and foundation flexibility was accounted for in a separate analysis. The results show that the theoretical bearing capacity increases substantially with depth, without the usual limit encountered during loading tests performed on deep foundations. It was found that most of this capacity is due to shaft friction, as the failure surface grows with embedment, causing shaft confinement to increase. Furthermore, it was shown that this theoretical capacity is too large to be reached in practice, since foundation flexibility combined with a bearing capacity definition based on a certain displacement at the top, always results in a partial mobilization of the theoretical base capacity and a small shaft capacity associated with in situ lateral confinement. However, comparison with actual measurements showed that, despite coming from a simple theoretical analysis, the capacity found here can still be used in practice. For shallow foundations, the total capacity can be employed directly, but for deep foundations the base capacity found in this study must be combined with a reasonable estimate of shaft friction in an analysis that accounts for foundation flexibility, such as the load transfer method.</p>