Method for estimating the weight of a motor vehicle comprising a front wheel assembly and a rear wheel assembly, using a smartphone, after the loading of the vehicle, the method comprising the steps of: (i) identifying the vehicle in the smartphone; (ii) using a camera of the smartphone to capture and process a photograph of at least one wheel with at least one point of the vehicle brought to sink down jointly upon the loading of the vehicle with the suspension of the wheel of the vehicle, after loading, in order to determine the clearance of the wheel assembly of the photographed wheel as a function of the identified vehicle, the taking of a photograph of a wheel is subordinate to keeping the smartphone in a plane at right angles to the plane of the photographed wheel except in the vertical position of the smartphone; (iii) determining the clearance of the wheel assembly opposite the wheel photographed in step (ii), either by measuring the angle of inclination of the vehicle after loading, using at least one accelerometer or inclinometer of the smartphone, or by capturing and processing a photograph of at least one wheel with at least one point of the vehicle brought to sink down jointly upon the loading of the vehicle with the suspension of a wheel of the wheel assembly opposite the wheel assembly of the wheel photographed in step (ii), using the camera of the smartphone; (iv) using a calculation unit of the smartphone to calculate the load value on the wheel assembly of the photographed wheel and the load value on the opposite wheel assembly as a function of the respective clearances of these wheel assemblies, to determine the total load value of the vehicle; (v) using the smartphone to inform the user of the load state of the vehicle. (i) identifying the vehicle in the smartphone; (ii) using a camera of the smartphone to capture and process a photograph of at least one wheel with at least one point of the vehicle brought to sink down jointly upon the loading of the vehicle with the suspension of the wheel of the vehicle, after loading, in order to determine the clearance of the wheel assembly of the photographed wheel as a function of the identified vehicle, the taking of a photograph of a wheel is subordinate to keeping the smartphone in a plane at right angles to the plane of the photographed wheel except in the vertical position of the smartphone; (iii) determining the clearance of the wheel assembly opposite the wheel photographed in step (ii), either by measuring the angle of inclination of the vehicle after loading, using at least one accelerometer or inclinometer of the smartphone, or by capturing and processing a photograph of at least one wheel with at least one point of the vehicle brought to sink down jointly upon the loading of the vehicle with the suspension of a wheel of the wheel assembly opposite the wheel assembly of the wheel photographed in step (ii), using the camera of the smartphone; (iv) using a calculation unit of the smartphone to calculate the load value on the wheel assembly of the photographed wheel and the load value on the opposite wheel assembly as a function of the respective clearances of these wheel assemblies, to determine the total load value of the vehicle; (v) using the smartphone to inform the user of the load state of the vehicle.