A theoretical strategy is developed to quantitatively assess the ion-beam damage as measured by Rutherford-backscattering spectrometry under channeling conditions (RBS/C) in LiNbO3 crystals. The approach is based on a recent exciton decay model to calculate the concentration of defects generated by the incoming ions as a function of their stopping power. To describe the channeled RBS yield the model takes into account the amorphous (core) as well as the defective halo contributions to the defect tracks caused by the ion impacts. It is concluded that the halo may significantly influence the assessed damage.