https://en.wikipedia.org/wiki/LGBT_demographics_of_the_United_States

The demographics of sexual orientation and gender identity in the United States have been more accurately studied in the social sciences in recent decades. In the first large-scale government survey measuring Americans’ sexual orientation, the NHIS reported in July 2014 that 1.6 percent of Americans identify as gay or lesbian, and 0.7 percent identify as bisexual.[1] In a Williams Institute review based on an June–September 2012 Gallup poll, approximately 3.4 percent of American adults identify themselves as being LGBT (lesbian, gay, bisexual, or transgender).[2] An earlier report published in April 2011 by the Williams Institute estimated that 3.8 percent of Americans identified as gay/lesbian, bisexual, or transgender: 1.7 percent as lesbian or gay, 1.8 percent as bisexual, and 0.3 percent as transgender.[3] The 2011 Williams Institute report also states that 8.2 percent of Americans reported that they had engaged in same-sex sexual behavior, and 11 percent reported some same-sex attraction. Studies from several nations, including the U.S., conducted at varying time periods, have produced a statistical range of 1.2[3] to 6.8[4] percent of the adult population identifying as LGBT. Online surveys tend to yield higher figures than other methods,[4] a likely result of the higher degree of anonymity of Internet surveys, which elicit reduced levels of socially desirable responding.[5]