Abstract: Method of estimating the volume of fuel in the tank of a motor vehicle, in which a measurement of the level of the fuel in the tank is made using a level sensor, this level sensor constituting a first information source whose signal is disturbed by a scale factor depending on values other than the level of the fuel, in particular the temperature, n other information sources are used relating to n different values other than the fuel level and making it possible to make the scale factor observable and the results provided by the (n+1) information sources are processed in order to estimate the scale factor, n being an integer greater than or equal to 1, according to which use is made of a second information source capable of providing information relating to the flow rate of the fuel consumed by the vehicle.