A combined experimental and numerical study is presented in order to predict fretting crack propagation. It rests on 2D and 3D fretting tests, with carefully controlled loading conditions leading to cracking as the main material response, the extraction of 2D and 3D crack geometry from post-mortem cross-sections, a three-dimensional X-FEM model based on a three field weak formulation accounting for 3D non-planar frictional crack and the level set formalism authorising a direct use of actual reconstructed crack shape, the stress intensity factors quantification, a mixed mode Paris law identification and finally the crack growth simulation. The 2D fretting tests are numerically simulated. The mixed mode crack growth law identified is then used to simulate the fretting crack growth. A very good agreement with experimental results is obtained. Then 3D fretting tests are simulated and the crack fronts are compared with actual ones.