Gel fraction data from linear low-density polyethylene (LLDPE) films and high-modulus polyethylene (HMPE) fibers, which had previously failed to give reasonable results when treated with Charlesby-Pinner and Saito-Kang-Dole theory, have been fitted to a modified form of the Wanxi equation. The fitting yields parameters that compare very well with literature values derived by the Wanxi equation, confirming that fracture and cross-linking densities are proportional to a power function (beta) of the radiation dose. Extrapolated G (S) values have been obtained from LLDPE using the fit parameters and UV-Vis spectroscopy data. A brief synopsis of the empirical analytical methods available for gel fraction analysis is given. 1994 John Wiley & Sons, Inc.