REUTERS/Robert Galbraith
According to a study published by the company, the members of its user base - made up of roughly 1.4 billion people - are separated by around 3.57 connections.
Six degrees of separation is a commonly accepted idea about how connected the human race is with each other.
Everyone, from Barack Obama to the Pope to an average Facebook user, is around six connections from everyone else, according to the theory.
The idea was immortalized in a play, called "Six Degrees of Separation," and has been born out in various studies, such as the small-world experiment, which was conducted by Stanley Milgram, a researcher at Harvard.
"Each person in the world (at least among the 1.59 billion people active on Facebook) is connected to every other person by an average of three and a half other people," write Sergey Edunov, Carlos Diuk, Ismail Onur Filiz, Smriti Bhagat, and Moira Burke, who conducted the study.
In the US, people are more closely connected - 3.46 degrees compared to 3.57 worldwide - according to the research.
Facebook's scientists created an algorithm to work out how separated its users are. The task was "monumental," according to the company, as "the number of people reached grows very quickly with the degree of separation."
A full description of how the result was reached is available on the website.
The results of Facebook's study concur with other research that suggests the world is getting smaller. Research conducted by Cornell University, the UniversitÀ degli Studi di Milano, and Facebook suggested that people were around four degrees separated in 2011.