A report from an American think-tank has estimated 1.57 billion Muslims populate the world - with 60% in Asia.
The report, by the Pew Forum on Religion and Public Life, took three years to compile, with census data from 232 countries and territories.
It showed that 20% of Muslims lived in the Middle East and North Africa.
The data also showed that there were more Muslims in Germany than in Lebanon, and more in Russia than in Jordan and Libya together.
Surprise
Researchers analysed approximately 1,500 sources including census reports, demographic studies and general population surveys.
Senior researcher Brian Grim told CNN that the overall figure was a surprise and said: "Overall, the number is higher than I expected."
MUSLIM POPULATION BY REGION
Asia and the Pacific: 61.9%
Middle East - North Africa: 20.1%
Sub-Saharan Africa: 15.3%
Europe: 2.4%
Americas: 0.3%
The report, published on Wednesday, also found that Ethiopia has nearly as many Muslims as Afghanistan.
Amaney Jamal, an assistant professor of politics at Princeton University, told the AP news agency: "This whole idea that Muslims are Arabs and Arabs are Muslims is really just obliterated by this report."
Instead the report found that more than 300 million Muslims live in countries where Islam was not the majority religion.
Of the total Muslim population, 10-13% are Shia Muslims and 87-90% are Sunni Muslims.
Most Shias live in Iran, Pakistan, India and Iraq.
Europe is home to 38 million Muslims - around 5% of its population with European Muslims making up slightly more than 2% of the world's Muslim population.
More than half of the 4.6 million Muslims in the Americas live in the US - however they make up just 0.8% of the population there.
The Pew Forum has said the findings will lay the foundation for a forthcoming study that will look at how Muslim populations worldwide have grown and what they may look like in the future.
It also plans to compile figures for the other major world religions.
According to internet-based group, Adherents, there are currently 2.1 billion Christians, 900 million Hindus and 14 million Jews worldwide.
