An analytical model of segregation at grain boundaries, which takes into account all five macroscopic parameters of grain boundary character, has been developed. The model is based on a combination of previous bond energy treatments of grain boundary energy and of segregation to free surfaces. It is tested by comparing its predictions against previous computations of segregation to symmetrical twist grain boundaries in simple fcc alloys obtained by Monte Carlo simulations in conjunction with embedded atom method potentials. The comparison shows good agreement with the previous computer simulations. Examples of model predictions in the case of asymmetric grain boundaries are also provided. (C) 2005 Springer Science + Business Media, Inc.