The cone penetration test (CPT) is used to characterize the behaviour and properties of soils, including the susceptibility to earthquake liquefaction triggering. Liquefaction susceptibility relates to the relative density of soils; and cone tip resistance also closely relates to relative density. Currently, published methods of estimating liquefaction potential (i.e., cyclic resistance ratio) are based on silica sands and do not properly characterize calcareous sands. The measured cone tip resistance in calcareous sands is lower than silica sands at the same relative density (i.e., Boulanger & Idriss 2016); this difference is attributed to the higher compressibility of calcareous sands due to particle crushing during cone penetration. Consequently, engineers could misinterpret the liquefaction potential of calcareous sands, resulting in over-conservatism in design. This study works to characterize the role of compressibility and crushability of calcareous sands on the cone tip resistance using a direct axisymmetric penetration model and the MIT-S1 constitutive model (Moug et al. 2017, Pestana and Whittle 1999) calibrated against published mechanical properties for calcareous sands (Giretti et al. 2018). The MIT-S1 model was chosen due to its ability to capture compression behaviour at high stresses, such as during cone penetration. The motivation of this study is to develop better relationships between the relative density of calcareous sands and cone tip resistance, as well as develop methods to correct tip resistance for soil crushability to use established CPT correlations.