Non-elastic cross-sections have been calculated by using optical model for (n, 3He) reactions at 14-15 MeV energy. The new empirical formula including optical model non-elastic effects by fitting two parameters for the (n, 3He) reaction cross-sections have been suggested. The excitation function character and reaction Q-values depending on the asymmetry term effect for the (n, 3He) reaction have been investigated. The obtained cross-section formula with new coefficients has been compared with the experimental data and the other fitting formulae existed in the literature and discussed. It has seen that the fit of new formula in this paper is greatly improved with the experimental data. © 2009 Springer Science+Business Media, LLC.