World leaders have set a goal of gender equality by 2030, yet experts caution that it can’t happen if data gaps are not solved. One noted, “Data saves lives. It captures the attention of policy makers and focuses their efforts on the right issues.” That is, as advocates put it, we must “count women” if we are to garner large-scale support and resources for women and girls. To learn what this emphasis looks like in implementation, I asked international development practitioners how gender-related measurement is carried out at their project sites—and with what effects? What I heard resonates with the words of former USAID Administrator Andrew Natsios: focusing on measurement is important, yet it also “ignores a central principle of development theory… programs that are [the] most transformational are the least measurable.”