A method for determining the geometry of a raw part, which is shaped to form a finished part in a hydroerosive grinding method, comprising the following steps: (a) creation of a structural model of the finished part to be produced, the structural model of the finished part to be produced being used as an initial model for the first execution of the next step (b); (b) mathematical simulation of the hydroerosive grinding method, with which an intermediate model with a modified geometry is produced starting from the initial model; (c) comparison of the intermediate model produced in step (b) with the structural model of the finished part and determination of the distance, orthogonal to the surface of the structural model of the finished part, between the structural model of the finished part to be produced and the intermediate model at each node of the structural model, and comparison of the orthogonal distance with a predetermined limit value; (d) creation of a modified model of the component by adding from 5 to 99% of the distance determined in step (c) with the opposite sign at each node on the surface of the model which is used as the initial model in step (b), orthogonally to the surface, and repetition of steps (b) to (d), the modified model created in step (d) being used as a new initial model in step (b) if the orthogonal distance determined in step (c) at at least one node is greater than the predetermined limit value; (e) termination of the simulation when the orthogonal distance determined in step (c) between the structural model of the finished part and the intermediate model at each node falls below a predetermined limit value, the initial model of the step (b) carried out last corresponding to the raw part geometry to be determined; (f) producing the determined raw part. (a) creation of a structural model of the finished part to be produced, the structural model of the finished part to be produced being used as an initial model for the first execution of the next step (b); (b) mathematical simulation of the hydroerosive grinding method, with which an intermediate model with a modified geometry is produced starting from the initial model; (c) comparison of the intermediate model produced in step (b) with the structural model of the finished part and determination of the distance, orthogonal to the surface of the structural model of the finished part, between the structural model of the finished part to be produced and the intermediate model at each node of the structural model, and comparison of the orthogonal distance with a predetermined limit value; (d) creation of a modified model of the component by adding from 5 to 99% of the distance determined in step (c) with the opposite sign at each node on the surface of the model which is used as the initial model in step (b), orthogonally to the surface, and repetition of steps (b) to (d), the modified model created in step (d) being used as a new initial model in step (b) if the orthogonal distance determined in step (c) at at least one node is greater than the predetermined limit value; (e) termination of the simulation when the orthogonal distance determined in step (c) between the structural model of the finished part and the intermediate model at each node falls below a predetermined limit value, the initial model of the step (b) carried out last corresponding to the raw part geometry to be determined; (f) producing the determined raw part. <EOS>