Polyethylene wear debris induced aseptic loosening is the leading cause of long-term failure in total hip replacements. The wear of polyethylene is a complex, multifactorial process. A finite element-based computational wear simulation was developed to help sort out some of the factors involved in the wear process. Different three-dimensional contact finite element models of total hip replacements were created. The loads for the finite element models came from either a physically validated gait analysis of a patient with an instrumented total hip or a load profile from a biaxial rocking hip simulator. Finite element analysis was used to determine the contact stress distributions for the discretized load profiles. Sliding distances of points on the femoral head were obtained from the corresponding full-triaxial motion gait or simulator kinematics. A separate custom-written computer program used a variation of the Archard equation relating contact stress, sliding distance, and a wear coefficient to determine wear rates. Through the use of adaptive remeshing, the computational wear formulation was able to simulate polyethylene removal, and hence, long-term wear. The computational simulation found that volumetric wear rates were strongly proportional to increases in femoral head sizes. Once congruency was achieved between the femoral head and acetabular component through wear-in, decreases in polyethylene thickness and variations within current industrial size tolerances for femoral heads had little effect on wear rates. A comparison between a biaxial rocking simulator and human gait, scaled so that the loading profiles had the same peak loads, showed that the hip simulator produced nearly twice the volumetric wear as the simulation of human gait, with a different wear front. Support conditions for the total hip models were found to have little effect on wear rates. Finally, the computational simulation was able to reproduce volumetric wear amounts that had been measured from cups physically worn in an actual hip simulator. The computational simulation was able to reproduce trends seen in clinical and in physical hip simulators, in a fraction of the time it would take to carry out the actual wear tests.