Method and device for controlling a boost pressure of a charged combustion engine

The method involves controlling an exhaust-gas turbocharger by a controller. The achieved loading pressure of the controller is set in the exhaust-gas turbocharger. An operating parameter of the exhaust-gas turbocharger is calculated in a function to reach the charging pressure. A turbine of the exhaust-gas turbocharger is taken into account for a turbine efficiency in the calculation of a size. An independent claim is included for a device for controlling a supercharging pressure of a supercharged internal combustion engine.