The invention concerns a method for vertically calibrating a wear tool (20； 120) of an agricultural machine, the agricultural machine comprising said wear tool, the method comprising the steps of: - bringing the wear tool into contact with a reference surface (5； 45)； - measuring the value (A2； A4) of a position variable (A； L； H) related to the positioning of the wear tool when it is in contact with the reference surface； - determining the theoretical vertical positioning component (P2； P4) of the wear tool according the measured value (A2； A4), based on a reference curve (f1)； - determining a correspondence curve (f2) between a vertical positioning component (P(A)) of the wear tool and the position variable, by shifting the reference curve by a value (ΔP) equal to the theoretical vertical component.
