Axial Ratio Calculator
The Axial Ratio of Proteins can be estimated from the Perrin Factor (refer to Cantor & Schimmel 1980. Biophysical Chemistry Part II: Techniques for the Study of Biological Structure and Function. Freeman and Co., New York).
An axial ratio calculator based upon the work of Perrin is available from Wyatt Technology.
Alternatively, the SEDNTERP program developed by experts in biophysical characterization (Tom Laue, John Philo, David Hayes) may assist with the analysis of hydrodynamic size, shape, and hydration of proteins.