This paper presents an analytical model for the energy dispersion of 2D hole inversion layers. In our approach, the energy dispersion along a few principal directions is described according to a conventional non-parabolic model. Then the angular dependence of the energy to wavevector relation is approximated with an analytical expression that has no fitting parameters. The overall model represents an analytical, non-parabolic and anisotropic description of the hole energy dispersion in inverted layers and it is tuned by comparisons with a quantization model based on the k · p method. The computational efficiency of the model presented in this work is suitable for its implementation in a multi-subband Monte Carlo simulator.