 "The Equation" first broadcast on the Fox network in the United States on November 18, 2008. It was watched by an estimated 9.18 million viewers, earning a 4.1 / 10 ratings share among adults aged 18 to 49, meaning that it was seen by 4.4 percent of all 18- to 49-year-olds, and 11 percent of all 18- to 49-year-olds watching television at the time of broadcast. The episode also received a 5.6 / 8 ratings share among all households. Fringe and its lead-in show, House M.D., helped Fox win the night in the adult demographic, as it was Fringe's highest rating since the season's second episode. It was Fox's fifth ranked show for the week.
