The invention relates to a method for determining a transmission ratio in the drivetrain of a motor vehicle, comprising an engine, a clutch in series therewith, and a gearbox connected thereto, whereby, between the engine and the gearbox, a ratio is determined from the speed of the output shaft from the engine and the speed of the output shaft from the gearbox. Said method comprises the further steps: determination of a value for the instantaneous speed of the motor vehicle, processing the value of the instantaneous speed of the output shaft from the gearbox and the value of the instantaneous speed of the motor vehicle by means of a computer unit such that the transmission ratio of the vehicle components after the gearbox is determined.