In selecting and designing materials for certain engineering applications, the resistance to material damage or removal of material from contacting surfaces in relative motion is an important factor. To determine these properties, laboratory tests are routinely conducted on new materials using a variety of tribometers with different contact configurations (ball-on-flat, pin-on-disc, etc.). The wear volume is typically measured as a function of the process parameters. Existing theoretical models are either phenomenological or have been developed for sharp indenters. The present work proposes a mechanics-based model for the calculation of wear volume for “ball-on-flat” type of contact in severe and ultra-severe wear regimes using Hertzian cone crack analysis. Two important aspects, i.e. the critical load for transition to severe wear regime and the dependence of wear volume on load and material properties (toughness, elastic modulus) can be successfully predicted for any brittle material using the proposed model. In order to demonstrate this, the experimental results for three materials (Ti3SiC2, WC–ZrO2, TiCN–20Ni–10WC), with a broad range of properties, are compared to the predictions of this model and also to those from existing models.