A device for measuring the level of fuel in a motor vehicle tank, the device being of the type comprising: a base for fixing to a wall of the tank; a support hinged about a horizontal axis to the portion of the base inside the tank; a shoe carried at the bottom end of the support so that the shoe rests against the bottom of the tank; a resistor element carried by the support; a float carried by an arm which is hinged about a non-vertical axis to the support to track the level of fuel; and a cursor carried by the arm and engaging the resistor element to define a resistance which varies as a function of the level of liquid contained in the tank, wherein the shape of the shoe is such that regardless of the position of the bottom of the tank, due to possible deformation of the tank, whenever the level of fuel corresponds to the same minimum measurable depth, the arm of the float always occupies the same position relative to the support.