structural:reformatting, structural:scholar_edition, stylistic:tone
Spread and demographics

There are more than 900 million Protestants worldwide, among approximately 2.4 billion Christians. In 2010, a total of more than 800 million included 300 million in Sub-Saharan Africa, 260 million in the Americas, 140 million in Asia-Pacific region, 100 million in Europe and 2 million in Middle East-North Africa. Protestants account for nearly forty percent of Christians worldwide, and are more than one tenth of the total human population. Various estimates put the percentage of Protestants in relation to the total number of world's Christians at 33%, 36%, 36.7%, and 40%, while in relation to the world's population at 11.6% and 13%.

In European countries which were most profoundly influenced by the Reformation, Protestantism still remains the most practiced religion. These include the Nordic countries and the United Kingdom. In other historical Protestant strongholds such as Germany, the Netherlands, Switzerland, Latvia, and Estonia, it remains one of the most popular religions. Although Czech Republic was the site of one of the most significant pre-reformation movements, there are only few Protestant adherents; mainly due to historical reasons like persecution of Protestants by the Catholic Habsburgs, restrictions during the Communist rule, and also the ongoing secularization. Over the last several decades, religious practice has been declining as secularization has increased. According to a 2019 study about Religiosity in the European Union in 2019 by Eurobarometer, Protestants made up 9% of the EU population. According to Pew Research Center, Protestants constituted nearly one fifth (or 18%) of the continent's Christian population in 2010. Clarke and Beyer estimate that Protestants constituted 15% of all Europeans in 2009, while Noll claims that less than 12% of them lived in Europe in 2010.

Changes in worldwide Protestantism over the last century have been significant. Since 1900, Protestantism has spread rapidly in Africa, Asia, Oceania and Latin America. That caused Protestantism to be called a primarily non-Western religion. Much of the growth has occurred after World War II, when decolonization of Africa and abolition of various restrictions against Protestants in Latin American countries occurred. According to one source, Protestants constituted respectively 2.5%, 2%, 0.5% of Latin Americans, Africans and Asians. In 2000, percentage of Protestants on mentioned continents was 17%, more than 27% and 6%, respectively. According to Mark A. Noll, 79% of Anglicans lived in the United Kingdom in 1910, while most of the remainder was found in the United States and across the British Commonwealth. By 2010, 59% of Anglicans were found in Africa. In 2010, more Protestants lived in India than in the UK or Germany, while Protestants in Brazil accounted for as many people as Protestants in the UK and Germany combined. Almost as many lived in each of Nigeria and China as in all of Europe. China is home to world's largest Protestant minority.

Protestantism is growing in Africa, Asia, Latin America, and Oceania, while declining in Anglo America and Europe, with some exceptions such as France, where it was eradicated after the abolition of the Edict of Nantes by the Edict of Fontainebleau and the following persecution of Huguenots, but now is claimed to be stable in number or even growing slightly. According to some, Russia is another country to see a Protestant revival.

In 2010, the largest Protestant denominational families were historically Pentecostal denominations (11%), Anglican (11%), Lutheran (10%), Baptist (9%), United and uniting churches (unions of different denominations) (7%), Presbyterian or Reformed (7%), Methodist (3%), Adventist (3%), Congregationalist (1%), Brethren (1%), The Salvation Army (<1%) and Moravian (<1%). Other denominations accounted for 38% of Protestants.

The United States is home to approximately 20% of Protestants. According to a 2012 study, Protestant share of U.S. population dropped to 48%, thus ending its status as religion of the majority for the first time. The decline is attributed mainly to the dropping membership of the Mainline Protestant churches, while Evangelical Protestant and Black churches are stable or continue to grow.

By 2050, Protestantism is projected to rise to slightly more than half of the world's total Christian population. According to other experts such as Hans J. Hillerbrand, Protestants will be as numerous as Catholics.

According to Peter L. Berger, popular Protestantism is the most dynamic religious movement in the contemporary world, alongside resurgent Islam.