Facebook announced on Thursday it has one billion users.
The milestone was reached on 14 September. This is up by 45 million users since June.
The social media company has faced a rough road since its initial public offering in May. Facebook shares have lost more than 40% of their value since then.
The site was launched in 2004 at Harvard University and its users have befriended each other 140.3 billion times.
Chief executive Mark Zuckerburg also said about 600 million people access the site through mobile phones.
The median age of a Facebook user is 22 and the top five countries are Brazil, India, Indonesia, Mexico and the United States.
The BBC reports that sustained growth is seen as crucial if Facebook is to maintain its value - the company has seen its share price drop to about $US22 from a starting price of $US38.