Centrifugal compressors in gas-turbine engines and turbochargers operate with considerable external heat transfer. Measured compressor temperature enhancement does not permit to calculate performance by means of expressions for adiabatic process. Reduction of test data by the Universal modeling method based on assumption that work coefficient is linear function of a flow rate coefficient independent of compressibility allows calculating high-head centrifugal compressors gas-dynamic performances in case of non-adiabatic compression process.