Estimated efficiencies (left) and mass-loss rates (right) for fixed planetary mass M_p = 0.7 M_J but different EUV fluxes, from F_EUV = 100erg/s/cm² (red) to F_EUV = 10⁶ erg/s/cm² (orange). The efficiency of the traditional recombination-limited approach is shown with dashed curves. In the intense EUV flux case, our model predictions are almost the same as the traditional approach (orange and purple). The fitted efficiencies from detailed 1D simulations by Caldiroli et al. (2021) are shown as points. Some points of the strong-gravity case (M_p > 20 M_J) cannot be seen in this panel due to the low efficiency.