Two trends that are already underway - the decline of Christians and the growth of religiously unaffiliated people as a share of the US population are expected to continue in the decades ahead, said the Pew Research Center's projections of major religious groups around the world.
If current demographic trends hold, there also will be other significant changes in the US religious landscape: Judaism will no longer be the largest non-Christian religion in the country and by 2050 Muslims are projected to outnumber them, it said.
Muslims, due to their continued migration to the USA and high fertility rates, are expected to make up 2.1 per cent of the US population in 2050, up from 0.9 per cent in 2010.
Jewish people are projected to decline from an estimated 1.8 per cent in 2010 to 1.4 per cent in 2050. On average, Jews have 1.9 children per woman compared with 2.8 for US Muslims, the study said, adding that Muslims also have the youngest median age of any major religious group in America.
Muslims are not the only American religious minority that is growing. Hindus, who make up another relatively young group that continues to be boosted by migration, are projected to double from 0.6 per cent in 2010 to 1.2 per cent in 2050.
Buddhist population will see a modest rise from 1.2 per cent to 1.4 per cent. Members of "other religions" (a category for all those not categorized elsewhere in the projections, including Sikhs, Wiccans and Unitarian Universalists) are projected to increase from 0.6 per cent in 2010 to 1.5 per cent in 2050, it said.
Adherents of folk religions are forecast to increase from 0.2 per cent to 0.5 per cent.