Protestants worldwide are estimated to be around 800 million, among approximately 2.3 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 35% of Christians worldwide and more than one tenth of the total human population. Various estimates put the percentage of Protestants in relation to the total number of the world's Christians at 33%, 36%, 36.7%, and 40%, while in relation to the world's population at 11.6% and 13%.
Within Europe, Protestantism remains the most practiced religion in the Nordic countries and United Kingdom. In other historical Protestant strongholds such as Germany, the Netherlands, Switzerland, Latvia, Estonia and Hungary, it remains one of the practiced 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, Protestant practice has been declining as secularization has increased. According to a 2019 study about religiosity in the European Union (EU) by Eurobarometer, Protestants made up only 9% of the EU population. According to Pew Research Center, Protestants constituted nearly one fifth (or 17.8%) 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.