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An off-design performance loss model was developed for variable-stator (pivoted vane), radial turbines through analytical modeling and experimental data analysis. Stator loss is determined by a viscious loss model; and stator vane end-clearance leakage effects are determined by a clearance-flow model. Rotor loss coefficients were obtained by analyzing the experimental data from a turbine rotor previously tested with six stators having throat areas from 20 to 144 percent of design area and were correlated with stator-to-rotor throat area ratio. An incidence loss model was selected to obtain best agreement with experimental results. Predicted turbine performance is compared with experimental results for the design rotor as well as with results for extended and cutback versions of the rotor. Sample calculations were made to show the effects of stator vane end-clearance leakage. (Author)