The main problem with silicone implants in augmentation mammaplasty and breast reconstruction is the development of capsular contracture. The universal method for evaluating the degree of firmness of the breast is the subjective palpation technique and the classification according to Baker. Many objective methods using calipers for measurements of compression, different devices for indentation and discs for applanation tonometry have been described, but none of these have been widely accepted. In this paper a new measuring instrument is presented based on the principle of a constant compression force between two caliper jaws applied to the breast. The inverse value of the compressibility of the breast is read on a scale on the device. This objective method correlates acceptably with the palpation technique according to the Breast Augmentation Classification (BAC) (12), which is a modification of Baker's classification (1978), except for the first follow-up.