Executive SummaryIncreasing numbers of population-based surveys in the United States and across the worldinclude questions that allow for an estimate of the size of the lesbian, gay, bisexual, andtransgender (LGBT) population. This research brief discusses challenges associated withcollecting better information about the LGBT community and reviews eleven recent US andinternational surveys that ask sexual orientation or gender identity questions. The briefconcludes with estimates of the size of the LGBT population in the United States.Key findings from the research brief are as follows: An estimated 3.5% of adults in the United States identify as lesbian, gay, or bisexual andan estimated 0.3% of adults are transgender. This implies that there are approximately 9 million LGBT Americans, a figure roughlyequivalent to the population of New Jersey. Among adults who identify as LGB, bisexuals comprise a slight majority (1.8% comparedto 1.7% who identify as lesbian or gay). Women are substantially more likely than men to identify as bisexual. Bisexualscomprise more than half of the lesbian and bisexual population among women in eightof the nine surveys considered in the brief. Conversely, gay men comprise substantiallymore than half of gay and bisexual men in seven of the nine surveys. Estimates of those who report any lifetime same-sex sexual behavior and any same-sexsexual attraction are substantially higher than estimates of those who identify as LGB.An estimated 19 million Americans (8.2%) report that they have engaged in same-sexsexual behavior and nearly 25.6 million Americans (11%) acknowledge at least somesame-sex sexual attraction. Understanding the size of the LGBT population is a critical first step to informing a hostof public policy and research topics. The surveys highlighted in this report demonstratethe viability of sexual orientation and gender identity questions on large nationalpopulation-based surveys. Adding these questions to more national, state, and localdata sources is critical to developing research that enables a better understanding of theunderstudied LGBT community.https://williamsinstitute.law.ucla.edu/wp-content/uploads/Gates-How-Many-People-LGBT-Apr-2011.pdf