Historically, researchers and policy planners have selected a single indicator to measure trends in social inequalities. A more rigorous approach is to review the literature and data, select appropriate inequality measures to address the research question, compute results from various indices, and graphically compare resulting trends. The Health Disparities Calculator (HD*Calc, version 1.2.4; National Cancer Institute, Bethesda, MD) computes results from different indices and graphically displays them, making an arduous task easier, more transparent, and more accessible.