An electrical indicator for indicating the fuel content of a motor-vehicle tank comprises an elongate container (2) having a length corresponding substantially to the depth of the tank, intended to be arranged vertically in the tank, and an elongate float (22) slidable axially in the container (2). A rheostat including a resistor (31) and a slider (32) which cooperate with each other enables an electrical signal indicative of the fuel level in the tank to be provided. Axial biasing means are also provided for urging the float (22) towards the bottom (5) of the container (2) and are not interposed between the float (22) and the top (9) of the tank (2).