Carcass measurements for 185 market hogs representing two sexes and four body types, slaughtered at 91 to 132 kg, were examined as predictors of carcass composition. Dependent variables included weight of fat-standardized lean (FSL), percentage FSL in the standardized side, weight of FSL gained/day on test, and weight of FSL produced/day of age. The greatest degree of predictive accuracy in each equation occurred when longissimus muscle area and fat depth at the three-fourths location at the 10th rib were included as independent variables. Other important variables were hot carcass weight in the three equations predicting weight for FSL, age in the equation for FSL produced/ day of age, and initial weight on test and days on test for the prediction of FSL gained/day on test. Less accuracy was found when other back-fat thickness measurements or subjective scores of muscling or fatness were used as independent variables.