Spectropolarimetric data allow for simultaneous monitoring of stellar chromospheric logR'HK activity and the surface-averaged longitudinal magnetic field, Bl, giving the opportunity to probe the relationship between large-scale stellar magnetic fields and chromospheric manifestations of magnetism. We present logR'HK and\or Bl measurements for 954 mid-F to mid-M stars derived from spectropolarimetric observations contained within the PolarBase database. Our magnetically active sample complements previous stellar activity surveys that focus on inactive planet-search targets. We find a positive correlation between mean logR'HK and mean log |Bl|, but for G stars the relationship may undergo a change between logR'HK~-4.4 and -4.8. The mean logR'HK shows a similar change with respect to the logR'HK variability amplitude for intermediately active G stars. We also combine our results with archival chromospheric activity data and published observations of large-scale magnetic field geometries derived using Zeeman-Doppler Imaging. The chromospheric activity data indicate a slight under-density of late-F to early-K stars with -4.75<=logR'HK<=-4.5 . This is not as prominent as the original Vaughan-Preston gap, and we do not detect similar under-populated regions in the distributions of the mean |Bl|, or the Bl and logR'HK variability amplitudes. Chromospheric activity, activity variability, and toroidal field strength decrease on the main sequence as rotation slows. For G stars, the disappearance of dominant toroidal fields occurs at a similar chromospheric activity level as the change in the relationships between chromospheric activity, activity variability, and mean field strength.

Cone search capability for table J/MNRAS/514/4300/tables (Chromospheric S-index and surface averaged longitudinal field strengths (tables 1 and 3 of the paper))