Health literacy is broadly defined as "the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions." But just how is this degree measured? The Health Literacy Tool Shed provides information on various "health literacy measurement tools," and helps users find appropriate resources to meet their needs. Before diving into the database, readers may want to look over the Glossary page, which explains the terminology used throughout the site. Then, visitors can browse the more than 100 measures on the Find Measures page. Users may also opt to apply filters, including: "health literacy domain measured" and "approximate administration time in validation study." Clicking on a measure reveals a pop-up screen that summarizes its characteristics and psychometric properties, as well as a link to view in-depth information about the measure. While most measures are free, readers should note that the site does not "exclude tools on the basis of accessibility, so some tools may require payment or author permission." The Suggest a Measure tab at the top of the page also welcomes readers' suggestions for new materials to add to the site. Michael Paasche-Orlow (MD, MA, MPH) leads the project, in partnership with Boston University, RTI International, and CommunicateHealth, Inc. The project is financially supported by the National Institutes of Health's National Library of Medicine.