Obtaining precise numbers on the demographics of sexual orientation is difficult for a variety of reasons, including the nature of the research questions. Most of the studies on sexual orientation rely on self-reported data, which may pose challenges to researchers because of the subject matter's sensitivity. Some studies examine self-reported data on same-sex sexual experiences, while other studies examine self-reported identification as homosexual, heterosexual or bisexual. Overall, fewer research subjects identify as homosexual or bisexual, than report having had sexual experiences or attraction to a person of the same sex. Survey type, questions and survey setting may affect the respondents' answers.
General findings A 2016 literature review stated that "Four related phenomena fall under the general rubric of sexual orientation, but they are conceptually and empirically distinguishable. They are listed here not in order of importance but in an order that reflects their degree of historical attention. The first phenomenon, sexual behavior, consists of sexual interactions between persons of the same sex (homosexual), the other sex (heterosexual), or both sexes (bisexual). The second phenomenon, sexual identity, is one's self-conception (sometimes disclosed to others and sometimes not) as a homosexual, bisexual, or heterosexual person. The third phenomenon of sexual orientation is one's degree of sexual attraction to the same sex, both sexes, or the other sex. The fourth phenomenon is one's relative physiological sexual arousal to men versus women (or to male vs. female erotic stimuli), which is more closely related to other aspects of sexual orientation in men than in women." They state that there is no persuasive evidence that the demographics of sexual orientation have varied much across time or place. Bisexuality comes in varying degrees of relative attraction to the same or opposite sex. Men are more likely to be exclusively homosexual than to be equally attracted to both sexes, while the opposite is true for women.
Surveys in Western cultures find, on average, that about 93% of men and 87% of women identify as completely heterosexual, 4% of men and 10% of women as mostly heterosexual, 0.5% of men and 1% of women as evenly bisexual, 0.5% of men and 0.5% of women as mostly homosexual, and 2% of men and 0.5% of women as completely homosexual. An analysis of 67 studies found that the lifetime prevalence of sex between men (regardless of orientation) was 3–5% for East Asia, 6–12% for South and South East Asia, 6–15% for Eastern Europe, and 6–20% for Latin America. The International HIV/AIDS Alliance estimates a worldwide prevalence of men who have sex with men between 3 and 16 percent.
Estimating the demographics of sexual orientation on a global scale is a difficult task, because in many parts of the world discrimination has led people to conceal their sexual identities. Some cross-cultural research has suggested that male homosexuality is more prevalent in stratified societies and may not be a cultural universal, but the empirical findings, conceptual basis, and methodology of such research has been disputed by other cross-cultural researchers.
A small number of people do not feel sexual attraction and identify as asexual, which can be considered a sexual orientation in itself or a lack thereof.
By country Worldwide
2021 In 2021, Ipsos interviewed people in 27 countries spanning all continents on their sexual orientation and gender identity. For some countries the samples were weighed for representativity, but in others with less internet access, they skewed more urban. In this survey, on average about 80% of people worldwide identified as heterosexual, 3% as gay, lesbian or homosexual, 4% as bisexual, 1% as pansexual or omnisexual, 1% as asexual, 1% as "other", and 11% don't know or won't say. Results indicated that significant differences in sexual identity have emerged between generations across the globe, with the youngest group, or Generation Z, being more likely to identify as bisexual (9%) than Millennials (4%), Generation X (3%) and Boomers (2%). Generation Z and Millennials were also more likely to identify as homosexual, with 4% and 3% doing so respectively, compared to 2% of Generation X and 1% of Boomers. In addition, the survey found that men are more likely than women to identify as homosexual (4% vs. 1%).
Australia
2001–2002 The then largest and most thorough survey in Australia was conducted by telephone interview with 19,307 respondents between the ages of 16 and 59 in 2001/2002. The study found that 97.4% of men identified as heterosexual, 1.6% as homosexual and 0.9% as bisexual. For women 97.7% identified as heterosexual, 0.8% as lesbian and 1.4% as bisexual. Nevertheless, 8.6% of men and 15.1% of women reported either feelings of attraction to the same gender or some sexual experience with the same gender. Overall, 8.6% of women and 5.9% of men reported some homosexual experience in their lives; these figures fell to 5.7% and 5.0% respectively when non-genital sexual experience was excluded. Half the men and two thirds of the women who had same-sex sexual experience regarded themselves as heterosexual rather than homosexual.
2012–2013 An update on the above study; it employs the same methodology, has a larger sample (20,055 respondents), and a broader respondent age range (16–69). The study found that 96.5% of the entire sample (or 96.8% of the men and 96.3% of the women) identified as heterosexual, a drop from the 2003 findings (97.5%). Homosexuals accounted for 1.9% of the male population and 1.2% of the female population, a non-significant difference between the sexes. Bisexuals accounted for 1.3% of the male population and 2.2% of the female population. Women were significantly more likely than men to identify as bisexual, and less likely to report exclusively other-sex or same-sex attraction and experience. Similarly, more women reported same-sex experience and same-sex attraction. Nine percent of men and 19% of women had some history of same-sex attraction or experience. More women identified as lesbian or bisexual than in 2001–02. Homosexual/gay identity was more common among men with university education and living in cities, and much less common among men with blue-collar jobs. Both male and female bisexuality were more common among respondents under the age of 20. Male bisexuality was also overrepresented among men in their sixties.
2014 In interviews with 180,000 Australians aged 14+, Roy Morgan Research reported in 2014 that 4.1% of men and 2.8% of women identified as homosexual. Men outnumbered women among homosexuals in all age groups. For both sexes, the share identifying as homosexual was highest in the 20–29 age group.
The 2014 General Social Survey, conducted by the Australian Bureau of Statistics, estimated that over half a million people, or 3% of the adult population, identified as gay, lesbian, or 'other'.
2020 A study conducted by BioMed Central estimated that 3.6% of males and 3.4% of females were gay, lesbian, bisexual, or another sexual minority.
Austria A 2018 study reported that the percentage of people identifying as homosexual or bisexual in Austria was 6.2% (broken into 5.5% for males and 6.8% for females).
Brazil
1998 In a sample of 2,054 Brazilians aged 18 to 60 years of age, the Datafolha pollster found that 14% (or 15% of men and 13% of women) feel at least some same-sex attraction, while 70% did not feel any such attraction; the remaining 16% did not answer the question. Seventy-four percent of Brazilians said they never had a homosexual experience, 16% refused to answer the question, and 9% said they had some homosexual experience. The percentage with homosexual experience was higher among men (14%) than among women (5%), and higher also among those with more formal education (15%), singles (12%), and Northeasterners (11%). The non-religious (18%) and Pentecostal Protestants (11%) were more likely to have had homosexual experiences than Catholics (8%).
2013 In an Ibope survey with a sample of 2,363 Brazilian Internet users weighted for national representativity, 83% declared themselves heterosexual, 7% homosexual, 5% bisexual, 1% other, and 4% refused to disclose their orientation. Twice as many male internet users as females identified as gay or bisexual (16% vs. 8%). People aged 18–29 were the most likely to identify as non-heterosexual (15%), followed by those aged 30–49 (10%). Only 5% of the population aged 50 or more consider themselves gay or bisexual. Among non-heterosexuals, 42% said they had no religion, compared to 13% of the heterosexual population. The Class B (middle class) had the highest percentage of non-heterosexuals (14%), followed by Class A (upper class, 11%). Classes C and D (lower–middle and low classes) had 10% gays and bisexuals. Among the Brazilian regions, Northern Brazil had the lowest percentage of non-heterosexuals (2%). All other regions had percentages at or above 10%, with the Center-West reporting the highest (14%).
Canada
2003–2014: Canadian Community Health Survey Gay/lesbianBisexualTotal20031%0.7%1.7%20051.1%0.8%1.9%2007——2.1%20091.1%0.9%2.0%20121.3%1.1%2.4%20141.7%1.3%3.0%
2016 A female-only survey found that 8% of Canadian women identify as gay or bisexual.
2018 In 2018, around 4% of the Canadian population identified as LGBT, according to Statistics Canada.
Czech Republic 2015–2016 In 2015, around 7% of men and 10% of women identified as gay, according to a survey of around 30,000 people by the Faculty of Science at Charles University in Prague. However, it was a survey of sexual behaviour of Czechs and took about 90 minutes to complete, so only highly motivated people completed the survey. Research on sexual behaviour continued in 2016, with some surveys of the research receiving up to 40,000 responses. According to the research, the number of non-heterosexual men in the Czech Republic is 6.7%, and 11.5% of women. The researchers said the numbers did not seem right to them, and they verified them multiple times in other surveys with other people, but they believe the data are credible.
2023–2024 According to a CzechSex research conducted by the National Institute of Mental Health (), 3.1% of Czechs identify as bisexual, 2.0% as gay, and 0.6% as lesbian. An additional 0.3% of respondents selected "other," while both asexuality and pansexuality were each reported by 0.1%. 0.7% said they didn't know yet, while 1.9% people indicated they don't understand the question. The representative research combined online (4,660 respondents) and face-to-face survey (2,009 respondents), aged 18 to 75. It also focused on topics such as sexual disorders, pornography, partner seeking or first sexual intercourse.
Denmark A random survey found that 2.7% of the 1,373 men who responded to their questionnaire had homosexual experience (intercourse).
France
1992 A study of 20,055 people found that 4.1% of the men and 2.6% of the women had at least one occurrence of sexual relations with a person of the same sex during their lifetime.
2011