What is the current human population?
The most recent official numbers from the United Nations Population Division estimate that the world population was 6.9 billion in 2010. More recent estimates from the UN and the United States Census Bureau estimate that the world reached 7 billion inhabitants in either 2011 or 2012.
How do we measure world population?
The United Nations collects data on population, birth and death rates, age and gender ratios, and international migration from national-level censuses, surveys, and registers. The combination of data on fertility, mortality, and migration produces a comprehensive view of population in a given year. Most developed nations regularly conduct these sorts of demographic analyses, but for many developing countries, the data are scarce, unreliable, or nonexistent. In those cases, the UN relies on models and indirect estimates based on understandings of demographic trends and historical trajectories of similar nations.