Molar mass determination methods can be classed as absolute, equivalent, or relative. Absolute methods allow the molar mass to be directly calculated from the measured quantities without the need for assumptions concerning the physical and/or chemical structure of the polymers. In contrast, equivalent methods require a knowledge of the chemical structure of the macromolecules. Relative methods depend on the chemical and physical structure of the solute as well as on the solute-solvent interaction; these methods require calibration against another molecular mass determination method.