A braking force generator for a braking system. The braking force generator includes a drive shaft, rotatably mounted in a housing, an electric motor, which includes a rotor and at least one motor winding, an actuating element, which is displaceably mounted, and a transmission unit, which operates between the drive shaft and the actuating element in such a way that the actuating element is displaced during a rotation of the drive shaft. The transmission unit includes a planetary gear set encompassing a sun wheel connected to the drive shaft in a rotatably fixed manner, a rotatably mounted planet carrier, at least one planet wheel rotatably mounted at the planet carrier, and an output toothing assigned to the actuating element. The output toothing is formed in a lateral wall of an end area of the planet carrier facing away from the electric motor.