Abstract: Based on a film-thickness formula developed by author, derived are equations for calculating grease-lubricated ehd film-thickness between rolling elements and races of various types of rolling bearing. The dimensional details of the bearing elements, which are not known to the bearing users, are not needed in applying the equations. The calculation is simple and convenient and gives results of great accuracy. The calculated results are further verified by experimental ones. Some factors affecting the grease film thickness are discussed. Illustrative examples are given.