Same-sex marriage supporters celebrate a federal judge's decision overturning California's same-sex marriage ban on Wednesday, Aug. 4, 2010, in San Francisco. (AP Photo/Noah Berger)

(CNSNews.com) –While a recent Gallup poll showed that U.S. adults, on average, think homosexuals make up about 25 percent of the entire population, official data reveal that gays and lesbians comprise between 2 percent and 4 percent of the population.

In a May 5-8 telephone survey, Gallup asked more than 1,000 U.S. adults in all 50 states: “Just your best guess, what percent of Americans today would you say are gay or lesbian?”

The adults polled estimated that 25 percent – one quarter of all Americans – are gay or lesbian.

According to Gallup, over half of Americans (52 percent) said that at least one in five Americans is homosexual, and 35 percent estimated more than one in four. Only 30 percent estimated under 15 percent.

However, official estimates of the homosexual population range from 2 to 4 percent – well under the 25 percent “guesstimate.”

According to the U.S. Census Bureau, which began asking questions about same-sex household information in the 1990 Census, only 581,300 individuals were part of a same-sex household in 2009. That’s less than one-half of one percent (0.5 percent) of the 307 million people living in the U.S. in 2009.

Furthermore, data from the Census Bureau's 2010 Demographic Profile shows that “same-sex spouses” accounted for a mere 2.5 percent of the U.S. population, which is nearly 8 million people out of the total 309 million Americans.

The 2006-2008 National Survey of Family Growth found that 3.7 percent of adults aged 18 to 44 were homosexual or bisexual. The survey is administered by the National Center for Health Statistics, part of the federal Centers for Disease Control. It consists of an in-person interview in which the respondent enters his or her own answers into the computer without telling them to an interviewer.

The University of Chicago’s National Opinion Research Center, which has been conducting scientifically designed surveys on homosexuality for close to 30 years – far longer than the U.S. Census Bureau – found the percentage of gays, lesbians, and bisexuals in the United States in 2008 was 2 percent – a number that has been stable since the late ‘80s, according to Tom Smith, director of the General Social Survey at NORC. (pg. 57)

“In general, these figures have changed little from our first studies in the late 1980s through 2010,” Smith told CNSNews.com.

The Gallup poll was a random digit dial telephone interview which surveyed 1,018 adults, aged 18 and older, living in all 50 U.S. states and the District of Columbia on May 5-8, 2011. The margin of error was plus-or-minus 4 percentage points.