Known harvest weighing systems have problems associated with the disturbances from a moving harvester machine when attempting to weigh crops continuously. The invention relates to a process and harvester for weighing the harvested crop stored in at least one tank (9) supported by a frame (3) of a harvesting machine, said frame being mounted on a wheel set (2) by means of a lifting device (10) which is operable to move said frame upwardly and downwardly upon controlling a hydraulic system of said machine, said process comprising an acquisition procedure (C, D, E) wherein, upon controlling the hydraulic system for lowering and raising the frame (3) on a displacement course, the process providing for: determining at least one height position of the frame (3) on said course； measuring the lowering A1, B3 and the raising A2, B4 pressures in the hydraulic system at said position； calculating, from said measured pressures, a balancing pressure Pf, Pe for said frame； wherein said acquisition procedure is Performed before unloading the stored crop in order to calculate a loaded balancing pressure Pfand after said unloading in order to calculate an empty balancing pressure Pe, and the weight W of the stored crop is calculated from a pressure variation ∆P between said balancing pressures.
