Control device for a booster brake system of a vehicle, comprising: a first input device which is configured to receive a supplied first information item relating to a supplied assistance force (Fu) of a brake booster of the booster brake system: a second input device which is configured to receive a supplied second information item relating to a total force (Fg) composed of the assistance force (Fu) and a driver braking force (Ff) supplied by actuation of an activation element of the booster brake system; an evaluation device which is configured to define a third information item relating to a proportional relationship between the total force (Fg) and the assistance force (Fu) taking into account the first information item and the second information item; and an output device (44, 50) which is configured to supply at least one control signal (46, 52) to at least one component (14, 54) of the booster brake system taking into account the defined third information item relating to the proportional relationship between the total force (Fg) and the assistance force (Fu); characterized in that the second information item comprises at least a pressure (p) in the interior of a master brake cylinder of the brake system, an admission pressure (p) measureable by an admission pressure sensor, a wheel pressure (p) measureable by a wheel pressure sensor and/or a circuit pressure (p) measureable by a circuit pressure sensor, and the evaluation device is configured to define a probable driver braking force (Ff) taking into account the first information item and the pressure (p) as at least part of the third information item relating to a difference between the total force (Fg) and the assistance force (Fu). a first input device which is configured to receive a supplied first information item relating to a supplied assistance force (Fu) of a brake booster of the booster brake system: a second input device which is configured to receive a supplied second information item relating to a total force (Fg) composed of the assistance force (Fu) and a driver braking force (Ff) supplied by actuation of an activation element of the booster brake system; an evaluation device which is configured to define a third information item relating to a proportional relationship between the total force (Fg) and the assistance force (Fu) taking into account the first information item and the second information item; and an output device (44, 50) which is configured to supply at least one control signal (46, 52) to at least one component (14, 54) of the booster brake system taking into account the defined third information item relating to the proportional relationship between the total force (Fg) and the assistance force (Fu); characterized in that the second information item comprises at least a pressure (p) in the interior of a master brake cylinder of the brake system, an admission pressure (p) measureable by an admission pressure sensor, a wheel pressure (p) measureable by a wheel pressure sensor and/or a circuit pressure (p) measureable by a circuit pressure sensor, and the evaluation device is configured to define a probable driver braking force (Ff) taking into account the first information item and the pressure (p) as at least part of the third information item relating to a difference between the total force (Fg) and the assistance force (Fu). a second input device which is configured to receive a supplied second information item relating to a total force (Fg) composed of the assistance force (Fu) and a driver braking force (Ff) supplied by actuation of an activation element of the booster brake system; an evaluation device which is configured to define a third information item relating to a proportional relationship between the total force (Fg) and the assistance force (Fu) taking into account the first information item and the second information item; and an output device (44, 50) which is configured to supply at least one control signal (46, 52) to at least one component (14, 54) of the booster brake system taking into account the defined third information item relating to the proportional relationship between the total force (Fg) and the assistance force (Fu); characterized in that the second information item comprises at least a pressure (p) in the interior of a master brake cylinder of the brake system, an admission pressure (p) measureable by an admission pressure sensor, a wheel pressure (p) measureable by a wheel pressure sensor and/or a circuit pressure (p) measureable by a circuit pressure sensor, and the evaluation device is configured to define a probable driver braking force (Ff) taking into account the first information item and the pressure (p) as at least part of the third information item relating to a difference between the total force (Fg) and the assistance force (Fu).