Before 2040, Muslims will become the second largest religious group in the United States after Christians. By 2050, American Muslims will reach a population of 8.1 million.
According to the Pew Research Center, about 3.3 million Muslims were listed as living in the U.S. in 2015, representing 1 percent of the total U.S. population of 322 million.
The centre projects that the U.S. Muslim population will grow faster than the Hindus and much faster than Jews in the coming decades.
The new Muslim and other faiths estimates were based on a demographic projection since the centre's 2011 estimate. The study uses data on age, fertility, mortality, migration and religious switching drawn from multiple sources, including the 2011 survey of Muslim Americans.
"According to our current estimate, there are fewer Muslims of all ages in the U.S. than there are Jews by religion (5.7 million) but more than there are Hindus (2.1 million) and many more than there are Sikhs," wrote the centre's Besheer Mohamed.
In some U.S. cities, Muslims comprise more than 1 percent of the population such as New Jersey, which has two to three times as many Muslim adults per capita as the national average.
There is no official government data on Muslim population as the U.S. Census Bureau does not ask questions about religion, the Pew Center said.
"Since our first estimate of the size of the Muslim American population in 2007, we have seen a steady growth in both the number of Muslims in the U.S. and the percentage of the U.S. population that is Muslim," Mohamed said.
Half of the projected growth of American Muslims from 2010 to 2015 is because of immigration. The centre said in the last 20 years, there has been an increase in the number of Muslim migrants coming to the U.S.
"The number of Muslim immigrants currently represents about 10 percent of all legal immigrants arriving in the U.S., and a significantly smaller percentage of unauthorised immigrants," according to the centre.
The other main cause of Islam's recent growth is natural increase as American Muslims tend to have more children than Americans of other religious faiths.
"Muslims also tend to be younger than the general public, so a larger share of Muslims will soon be at the point in their lives when people begin having children," the centre explained.
It said there has been a little net change in the size of the American Muslim population in recent years due to conversion. About one in five American Muslim adults were raised in a different faith or none at all, the centre said.
"At the same time, a similar number of people who were raised Muslim no longer identify with the faith. About as many Americans become Muslim as leave Islam," Mohamed said.
