An interactive, meter-type graphical user interface (“GUI”) visually illustrates how the storage capacity of a physical or logical storage container is consumed by a number of items. Examples of items include physical units, logical units, or files of digital content. The items are arranged into a number of logical groups (each group including zero or more items) in accordance with user-selectable grouping criteria. The GUI displays group indicators in a manner that illustrates the relative amount of storage capacity consumed by each group (with respect to either total storage capacity or consumed storage capacity), and optionally by the individual items within each group. The GUI may also facilitate user manipulation of the items associated with each of the displayed groups, or suggest to the user how the unused storage capacity of a particular storage container may be consumed.