Left: comparison of two independent estimates of the total (H i + H₂) gas masses for the HRS galaxies, either using the dust mass and the metallicity as described in Sect. 4.3 (x axis) or using a more direct measurement from H i+CO spectroscopy (y axis). The black solid line shows the one-to-one relation, while the dotted line gives the best-fit linear trend (slope: 1.03 ± 0.03). Right: difference between these two independent gas mass estimates as a function of stellar mass. The black solid line is the line of perfect agreement, while the dotted line is the best-fit linear trend (slope: 0.01 ± 0.04).