The collection is a record for the month of January, which is considered sluggish for box office.
The Clint Eastwood-directed movie is the highest opening movie for the director, whose previous opening record was USD 29.5 million for 'Gran Torino'.
The film, despite a late release, did very well at the Oscar nominations picking up best actor and best picture nods.
Cooper plays Navy Seal sniper Chris Kyle in the drama that he started developing when Kyle was alive. Kyle, considered the deadliest sniper in American military while posted in Iraq, was shot dead in 2013 by a war veteran suffering from post traumatic stress disorder.