In one aspect, a device for measuring breast volume is disclosed, which comprises a housing comprising an enclosure having an opening, a flexible membrane sealingly covering said opening so as to provide an enclosed space within said enclosure, a gas disposed within said enclosed space, and at least one pressure sensor coupled to said enclosure so as to measure pressure of said gas within said enclosed space. The flexible membrane is configured to reversibly flex into said enclosed space in response to pressure of a breast against the membrane. The flexure of the membrane causes a change in the pressure and volume of the gas within said enclosed space.