The world has seen explosive growth in the use of estimates for key health indicators. UN agencies, such as WHO and UNICEF, and academic institutions, notably the Global Burden of Disease (GBD) work of the Institute of Health Metrics and Evaluation (IHME), have stepped up the frequency and scope of global health estimates. Funding agencies, led by the Bill and Melinda Gates Foundation, are making major investments in global health estimation. Several prominent, high-impact academic journals prioritise publication of global health estimates, which are usually received with great interest in the international health and development community and media.