Chess.com ratings versus OTB ratings

It's time for me to escape the screen and jump into the real world of OTB competition. But what can I realistically expect?

My rating here is in the 1800-1850 range. What would that translate to in a FIDE or USCF or ACF (Australian Chess Federation) rating?

My guess is that the difference would be around -300 points; that I could expect to achieve a 1500 rating at my current strength. Or is that overly optimistic?  

Yes, 1500-1600 would be a fair over the board rating estimate I believe.

That's a reasonable expectation : now go and get a taste of real chess !

For what it's worth, I would have guessed 1300s after looking at both live chess and your turn-based ratings... but there's really no way to tell, you certainly may be 1500-1600 and it's just that you aren't used to this live chess format.  The 1800+ turn based does imply you have the equivalent understanding.

Just remember at an OTB tournament you have to do all your blunder checking without an analysis board :)

There is huge variation. If you are not good at doing chess calculation in the head (which is really a limited form of blindfold chess) but you use an analysis board methodically, and also if you take advantage of opening books to play a GM level opening, you can play at a very much higher standard at turn-based chess than over the board. I have played at about 400 points higher (when I had the time to do it properly) but some (honest) players can  manage twice that. Turn-based chess is more different to OTB tournament chess than slowplay is to blitz, in my opinion, because the difference is not merely in the time available.

If you make more limited use of the analysis board, your rating might be only 200-300 different, I would guess.

Interesting reflections; thank you all:))

Including hicetnunc's imprecation to 'go play real chess' - gasp:)

Yes, the analysis board; it's true that you don't have one of those OTB! My intention, starting now, is to make my moves without using it in the next few games, and see what happens to my rating!

Also, I might change my Live chess behaviour. I tend to play that late at night/half asleep. I will try for 'awake and concentrated' sessions, and maybe 10 or 15m games, rather than the 5minute chuckstuff I generally do. 

Thanks again, chess.commers. 

Don't be discouraged if your OTB results are below 1500 at first- it takes time to get used to playing that way. You will be nervous, be unfamiliar with how to deal with draw offers, 50 move rule etc.

Just remember that the only pressure on you is what you put on yourself and the sooner you get out there and play the better. Getting some experience OTB will go a long way.

If you haven't played OTB at all then expect -500 or so points initially.  I would say the 300 point gap is reasonable for your existing potential based on what you know but OTB has other challenges.

True. It takes quite a while to reach your true level OTB.

I don't use the analysis board or opening databases, I play it like an OTB game, or as close as I can. I think subtracting 300 points from your rating would be close.