Precisely measuring the global Jewish population is difficult, because some people claim Jewish ancestry but are not practicing Jews. With this factor in mind, the global Jewish population is estimated to be approximately 13.5 million people, of which 60 to 70 percent are considered to be actively religious. Within this group, approximately 40 percent are Orthodox Jews, with the other 60 percent comprised of non-Orthodox Jews.

Populations by Region

The largest Jewish populations in the 21st century are located in the United States and Israel, with a total of 6 million Jews living in Israel as of March 2013 and roughly 5.5 million living in the United States. The third largest population is located in France, with an estimated population of roughly 500,000. While non-Orthodox Jews outnumber Orthodox Jews globally, in certain geographical regions Orthodox Jews form the majority.

New York City

In the United States, New York City has the highest concentration of Jews, with a population of about 1.1 million. Although still outnumbered by non-Orthodox Jews citywide, the Orthodox population in certain boroughs of New York City is increasing, with 40 percent identifying as Orthodox in 2012. This is an increase from 33 percent of identifying Orthodox Jews in 2002. The growth in Orthodox Jews is concentrated primarily in Hasidic communities. In certain parts of Brooklyn, Orthodox Jews form the majority of the population.

Israel

Much like New York City, the majority of practicing Jews in Israel are non-Orthodox. Currently, 10 percent of the total Jewish population is ultra-Orthodox, or Haredim. Unlike Hasidic Jews in the United States, Haredim in Israeli are legally allowed to refrain from military service and traditional work in order to dedicate their time to religious study. Proposals by the government to change this exemption in favor of a widespread compulsory conscription have elicited protests from some Haredim.

Non-Orthodox Population Trends

Between 2002 and 2011 in New York City, the Conservative and Reform groups of non-Orthodox Jews lost a total of 80,000 members. This trend is not uncommon among people who define themselves as Jews but have stopped participating in conventional rituals, holidays and religious practices. Due to a belief in family planning, many non-Orthodox Jews also have fewer children than their Orthodox counterparts.