Posterior distribution of the bolometric luminosity obtained from fitting the GRAVITY spectra of the 39 objects in the ExoGRAVITY Spectral Library with different atmospheric model grids. For each object, only the posteriors from the grids that provide a reduced χ² value close to the one of the best fitting model are shown. The median value and its uncertainties (16th and 84th percentiles) over all shown posteriors are shown by a black data point. We note that an additional systematic uncertainty of 10% (~ 0.05 dex) should be added in quadrature to the GRAVITY-derived luminosity when using it for further analyses to account for flux calibration errors. Where available, the literature values from Table 1 are shown as a black vertical line with a gray shaded area (bordered by dashed black lines) for the uncertainties.