The self-described nationalist, who was arrested last Wednesday, told investigators he wanted to kill Macron at the July 14 national day parade in Paris, a source close to the investigation said.
He said he also wanted to attack "Muslims, Jews, blacks, homosexuals," the source added.
Police arrested the man at his home in the northwest Paris suburb of Argenteuil on Wednesday after being alerted by users of a chatroom linked to a video game where he allegedly said he wanted to buy a firearm.
Three kitchen knives were found in his vehicle and analysis of his computer found that he had conducted internet searches on potential targets, the source said.
He was charged on Saturday with plotting to commit a terrorist act, the judicial source said.
The man was convicted for condoning terrorism in 2016 and sentenced to three years in prison, of which 18 months were suspended.
He had applauded neo-Nazi mass murderer Anders Behring Breivik, who killed 77 people in a bomb and gun rampage in 2011 in Norway.
The top date in France's ceremonial calendar, the July 14 parade commemorates the storming of the Bastille prison in 1789 -- the start of the French Revolution and a turning point in world history.
The parade takes place on Paris's Champs-Elysees, which has been the site of two recent attacks targeting police.
Late last month a man drove a car laden with weapons and gas canisters into a police van on the world-famous avenue.
In April, a known extremist shot dead a policeman on the Champs-Elysees just days before the first round of the presidential election.
Last July 14 saw the jihadist truck-ramming in southern Nice that left 86 people dead.
On Bastille Day in 2002, then president Jacques Chirac was the target of an assassination attempt on the avenue.
France has been under a state of emergency that has been repeatedly renewed since jihadist attacks in Paris in November 2015 in which 130 people were killed.