An apparatus for indicating a grain tank fill level for a grain tank (20) of an agricultural harvester (10), the harvester (10) having a chassis (12), an operator cabin (18) on the chassis (12); a threshing, separating, and cleaning means (24) on the chassis (12) for processing crop, a grain tank (20) on the chassis (18) for storing harvested grain and having an actual fill level of grain, a display (48) disposed in front of the operator in the direction of travel for displaying a fill level of the grain tank; a calculating means (46) coupled to the display (48) for calculating a fill level of the grain tank to be displayed on the display (48), and an operator input device (70) coupled to the calculating means (46) for selecting between first and second modes of operation, wherein the calculating means (46) is configured to repetitively and automatically calculate the fill level of the grain tank (20) in a first mode of operation and configured to repetitively and automatically indicate a scaled fill level that is scaled to a reference fill level different from the actual fill level in a second mode of operation, and further wherein the operator input device (70) is configured to indicate to the calculating means (46) the reference fill level when the operator input device (70) is selected by the operator.