M-R diagram for the planetary sample. The dots with error bars correspond to F planets (purple crosses), G planets (blue squares), K planets (red diamonds), and M planets (yellow pluses). Only G and K planets are used in the analysis. The solid colored curves are M-R relations for various theoretical models with different mass fractions of H-He and constant H₂ O mass fraction in the envelope (see Sect. 2.3 for details). The curves correspond to models with a T_eq of 700 K (shown as examples).