The invention relates to a method for determining the fatigue capital of a cable supporting a civil engineering structure, the method including: a measuring step (S1, S2) during which the normal tensile stress in the cable and the bending stress in the cable are measured in a synchronized manner so as to obtain the compound stress in the cable; a counting step (S3) during which a count of the number of stress cycles, depending on the amplitude of the stress, is carried out from the measured compound stresses; and a step (S4) of assessing the fatigue capital of the cable during which the fatigue capital of the cable is determined by comparing the count, carried out in the counting step, with a pre-set Wohler curve for the cable.