The traditional method of expressing sleeve bearing alloy load capacity, unit load, is at best only a gross approximation. Peak oil film pressure (POFP) is a much more meaningful parameter. A data base of Underwood fatigue machine test results on popular bearing materials was utilized to determine empirical constants in an equation relating POFP and cycles to failure. The resulting equation can be used to predict life at a given load level or the maximum allowable POFP for a given life. Material POFP ratings are established for connecting rod and main bearings subjected to varying types of service.