Energy-limited (green dots) and hydrodynamic (red crosses) mass-loss rates as a function of gravitational potential (GM_pl /R_pl) for two samples of planets with the same mass, stellar XUV irradiation, and equilibrium temperature (the parameters are listed at the top of each panel). The green and red lines show quadratic fits to the energy-limited and hydrodynamic mass-loss rates, respectively, in the form log Ṁ = . The coefficients p₀, p₁, and p₂ of the fits are listed in Table 3.