I read that for increment games the way to convert them to non-increment games for the purpose of classification by time control goes as follows:
Original time + Increment x 40 = Time used to classify
If you did read that (no reference given) then you read wrong. "Game time" is based on a game lasting 60 moves according to the latest FIDE rating regulations:
- Rate of Play
1.1 For a game to be rated each player must at the start of the tournament have the following minimum periods in which to complete all the moves, assuming the game lasts 60 moves
1 - So, for
120 minutes for the first 40 moves, 60 minutes for the next 20 moves, and then 15 minutes for the rest of the game, plus a 30-second increment per move starting from move 61.
the game time (time for first 60 moves) is 180 minutes (120+60+0) i.e. players have 180 minutes to play 60 moves
2 - For
The time control is 100 minutes for 40 moves followed by 50 minutes for 20 moves, then 15 minutes for the rest of the game, with a 30-second increment per move from move one
the game time (time for first 60 moves) is 180 minutes (100+50+30) i.e. players have 180 minutes to play 60 moves
3 - For
45 minutes for 40 moves plus 15 minutes for the rest, without increment
the game time (time for first 60 moves) is 60 minutes (45+15) i.e. players have 60 minutes to play 60 moves
4 - For
The time control (for both the group stages and the knockouts) will be 25 minutes per player for the first 30 moves, after which each player will receive additional 5 minutes on the clock and an increment of 5 seconds per move starting from move 31.
the game time (time for first 60 moves) is 32.5 minutes (25+5+2.5) i.e. players have 32.5 minutes to play 60 moves. That is 30 minutes for the first 30 moves then 5 minutes plus 2.5 minutes of increment for the next 30 moves.