This paper proposes an analytical approach to evaluate the ultimate embedment depth and holding capacity that plate anchors can potentially achieve. Based on a plasticity model for anchor-soil interaction and compatible chain solution, detailed derivations are presented that allow the main dimensionless groups of input parameters to be identified. For typical cases where the weight of the anchor is negligible relative to its holding capacity, explicit expressions are provided in non-dimensional form for ultimate embedment and anchor capacity. A thorough parametric sensitivity study highlights the major factors affecting these quantities. Two practical examples are considered that demonstrate the proposed analytical approach for different types of anchors, in one case revealing significant scope for improved design of plate anchors in order to optimise performance.