Analysis of information sources in references of the Wikipedia article "Demographics of atheism" in English language version.
Between 500 million and 750 million humans currently do not believe in God.
{{cite web}}: Missing or empty |url= (help)Secular/Nonreligious/Agnostic/Atheist: This is a highly disparate group and not a single religion. Although atheists are a small subset of this grouping, this category is not synonymous with atheism. People who specify atheism as their religious preference actually make up less than one-half of one percent of the population in many countries where much large numbers claim no religious preference...In most countries only a tiny number of people (zero to a fraction of 1 percent) will answer "atheism" or "atheist" when asked an open-ended question about what their religious preference... A slightly larger number answer "no" when asked simply if they "believe in God" (omitting wording indicating more nebulous, less anthropomorphic conceptions of divinity)...Estimates for atheism alone (as a primary religious preference) range from 200 to 240 million. But these come primarily from China and former Soviet Union nations (especially Russia).