A generalized model is presented for computing local void distribution, both radial and axial, in a light-water-moderated reactor channel. This model assumes that steam bubbles can be treated as free particles; thus, the continuity equation can describe the bubble motion. The model presented is considered to be particularly suitable for computer programming. It explicitly and simultaneously computes heat balance and conservation of mass, as well as void distribution. Furthermore, it provides sufficient flexibility to adjust constants in the equation so that any desired calculated void distribution can be obtained. Three existing pertinent void models constitute special cases of the proposed model.