Galaxy morphological classification
De Vaucouleurs also selected numerical values to each class of galaxy in his scheme. Values of the numerical Hubble stage T run from −6 to +10, with negative numbers going along with early-type galaxies (ellipticals and lenticulars) and positive numbers to late types (spirals and irregulars). So, as a rough rule, lower values of T go along with a larger fraction of the stellar mass contained in a spheroid/bulge relative to the disk. The close guess  mapping between the spheroid-to-total stellar mass ratio (MB/MT) and the Hubble stage is MB/MT=(10−T)2/256 based on local galaxies.