The invention relates to a method for calculating an AR overlay of additional information for display on an AR display unit, in particular a head-up display of a vehicle or smart glasses. The AR overlay is used to display a navigation route on the AR display unit. The navigation route is recalculated from time to time by a navigation system. The method is characterized in that the AR overlay is calculated in such a way that the recalculated route is displayed at least at a certain first distance before a branch-off point, and the driver is given an operating option of switching back and forth between the overview of the recalculated route and the previously calculated route.