The tournament has been a raging success and a total of 504,046 fans has watched the action in the 28 matches leading up to the semi-final stage.
This is an average of 18,000 spectators per match.
If Ange Postecoglou's team wins through to the final a crowd of 84,000 would be guaranteed at Stadium Australia in Sydney.
"As things stand we should be able to go past the 600,000 mark for the tournament which is way beyond our stretch target of 500,000," local organising committee chief executive Michael Brown said.
"If the Socceroos get to the final in Sydney on Saturday night we should be able to reach the figure of 650,000.
"This would be a credit to everybody involved in the event, particularly the fans who have supported the tournament all along.
"We are even getting people turning up after half-time so we have had to count the crowds at the 65th minute mark instead of at half-time."
The crowd projection is even more extraordinary when one considers that crowd-pullers Iran, China and Japan crashed out of the tournament in the quarter-finals.
Korea Republic plays Iraq in the first semi-final in Sydney on Monday night while Australia is up against UAE in Newcastle on Tuesday.
The match for third place takes place in Newcastle on Friday night.