Normalised Hα luminosities as a function of spectral type for CARMENES GTO sample with N_obs > 25. The solid orange line indicates the minimum values of emission in the Hα line that our CARMENES observations can detect, which is defined to be pEW (Hα) = −0.3 Å (Schöfer et al. 2019). A population of extremely active stars with pEW(Hα < −8.0 are indicated by the solid blue line as previously noted by Jeffers et al. (2018). Hα inactive stars are shown at the base of each plot as indicated by the y-axis. The stars in the CRX-slope sample are indicated by the diamond shapes which are coloured based on the CRX gradient of the data points in the left panel and CRX-length in the right panel. The stars are labelled as indicated in Table A.1.