FIDE rating VS Chess.com rating

If a players is rated say 1800 FIDE, on average what would his chess.com rating be. Will it be around 1800 as well or higher. Also does this comparison change as you go higher up the rating ladder?

1800 fide is like 2100 chesscom

1800 FIDE rapid = 1838 chess.com rapid
1800 FIDE blitz = 2104 chess.com blitz

Classical, rapid, blitz, bullet are different games requiring different skills and with different ratings. There are no conversions between them.

As long as ratings are stable
chess.com rapid = FIDE rapid + 38
chess.com blitz = FIDE blitz + 304

New new formulas everyday, @tygxc?

@4

No, refinement considering a sample of 10 instead of 1 Magnus Carlsen.

There was a sample of posters here and every single one of them that played both had much higher rapid than blitz. There was a well controlled survey sample of thousands of people and the pattern was that around 2000 or 2100 it starts to become more around level (blitz = rapid) and then at the very high ratings rapid is generally lower than blitz - but then no elite player takes rapid seriously and there's an IM number 1. I've said all this before, just saying it again for the benefit of others unfortunate enough to read your posts at this point.

@7

"every single one of them that played both had much higher rapid than blitz"
++ Rapid and blitz are different games, different skills, different ratings
You cannot convert between blitz and rapid.
You cannot derive a ping pong rating from a tennis rating or the other way around.
You cannot derive the time to run a marathon from the time to run a 100 m sprint.
You can only convert chess.com rapid to FIDE rapid and chess.com blitz to FIDE blitz.

"There was a well controlled survey"
survey < published ratings
Do all people respond truthfully to a survey?
Is there a bias who responds and who does not respond?

Online ratings are usually 200-400 points higher than your OTB rating

@11

Inbred ratings cannot be accurate.
That is why the FIDE rating floor has now been raised to 1400.

If some 1500 rated youngsters study chess all day and only play amongst themselves,
then they stay at 1500 rating even if their strength is up to 2500.
In my time the FIDE rating floor was 2200, so you could practically only get a FIDE rating by playing internationally.

I think the source Chess Rating Comparison – ChessGoals.com provides an answer to that. Although the methodology used has several limitations, it should give you a rough idea of how chess.com ratings translate to OTB ratings.