The branching ratio of a polymer relates to the number of branch units in a randomly branched polymer and the number of arms in star-branched polymers and was defined by Zimm and Stockmayer as
Where  is the mean square radius of branched and linear macromolecules with identical molar masses. By utilizing MALS in conjunction with a concentration detector as described above, one create a log-log plot of the root-mean-square radius vs molar mass. The slope of this plot yields the branching ratio, g.
In addition to branching, the log-log plot of size vs. molar mass indicates the shape or conformation of a macromolecule. An increase in the slope of the plot indicates a variation in conformation of a polymer from spherical to random coil to linear. Combining the mean-square radius from MALS with the hydrodynamic radius  attained from DLS measurements yields the shape factor ρ = , for each macromolecular size fraction.