Relative accessible surface area
Relative accessible surface area or relative solvent accessibility (RSA) of a protein residue is a measure of residue solvent exposure. It can be calculated by formula: RSA = ASA / MaxASA {\displaystyle {\text{RSA}}={\text{ASA}}/{\text{MaxASA}}} where ASA is the solvent accessible surface area and MaxASA is the maximum possible solvent accessible surface area for the residue.
Source: Wikipedia — Relative accessible surface area (CC BY-SA 4.0)