Comparison of analytical and empirical scale factors. Left: Scale factors measured from the HARPS post-MS sample plotted against values expected from the Basu & Chaplin (2017) analytical relations. The gray, dashed line shows equality. Right: Ratio of scale factor values expected from the Basu & Chaplin (2017) analytical relations (Eq. (5)) and measured from the HARPS post-MS sample. The black line was fitted as a correction factor to the analytic values as a function of effective temperature. Both: Markers are colored for surface gravity (based on MIST fits). Black edges indicate log g > 3.5, green 3.5 > log g > 3.0, and red 3.0 > log g. The marker shapes correspond to the evolutionary phases according to MIST: sub- or red giant (triangle), core Helium burning (squares), and asymptotic giant (diamonds).