Diamond wire sawing (DWS) of silicon wafers has replaced loose abrasive sawing (LAS) within a very short time, mainly due to the enormous cost pressure in the photovoltaic industry. However, the LAS process is still much better investigated and understood from a mechanics point of view. This lack of micromechanically substantiated process knowledge is a major challenge in optimisation for a reliable process and the associated improvement in the quality of the products. The present work aims to contribute to this field by deriving a material removal coefficient that can be used at the process level in well-established material removal laws such as the Preston or Archard equation. The results show that the removal coefficient calculated on the basis of finite element simulations indicates a significant increase in material removal for common DWS sawing conditions in comparison to LAS, which is in good agreement with experimental findings.