A portable digital scale is foldable for ease of storage and transport. The scale includes a fluid-filled elastomeric bladder and electronic module disposed in a hard-sided case that is opened in use and folded to encase the bladder and electronic module during transport and storage. The electronic module includes a pressure sensor for detecting the fluid pressure in the bladder as a measure of the user's weight, and a user interface and digital display for displaying the weight and/or other parameters requested by the user. Preferably, the electronic module includes a memory device capable of storing multiple weight measurements and a data port for down-loading stored weight data to a personal computer or PDA for tracking weight variation of one or more users over time.