usually its less for instance my rapid online is abt 1640 whereas my otb uscf rating is abt 1000 however it really depends bc a am newer to uscf ratings (its a provisional rating) and it really depends on the player bc i am better online disregarding rating i just make better moves online
Based on my online rapid rating what should my OTB rating be?

There's already been some studies of that and surveys, here's one from 2016 Chess Rating Comparison 2016 - Chess.com . Generally, online will be higher than OTB. If I had to make a guess, reason for that would be different view and psychological? Not an expert tho.

Depends on each individual chess players, but if I have to guess and estimate, I think your obt rating should fall anywhere between 700-1100. My rating here on chess.com is around 1600 and my otb rating is 1209.
I find the -300 rule to be relatively accurate. My USCF is 1800 or so, my rapid is 2100. I have a friend who is 2300 in all online categories and has hovered around 2k USCF for years.

it's about the same https://chessgoals.com/rating-comparison/

Whoever is downvoting the three or four people who said OP would be about 1100 needs to stop, because they aren't wrong.

There's already been some studies of that and surveys, here's one from 2016 Chess Rating Comparison 2016 - Chess.com . Generally, online will be higher than OTB. If I had to make a guess, reason for that would be different view and psychological? Not an expert tho.
i think the reason is just that otb ratings are less inflated than online ratings; you play about the same level otb vs online i think.

i mean im 2000 rapid chess com and not even 1000 uscf, but i think the reason for that is that im a bit overrated chess.com and i play against a bunch of underrated people otb. also i havent done that many tournaments.

its all the same when you have played 200 matches and still haven't won a single game... both are zero

All chess ratings depend upon activity to accurately estimate a player's strength. People who do not play over the board regularly are not going to have an accurate rating for example.

I am 1800 on chess.com and my OTB rating is 1500. I did stop in the middle because of the pandemic, but I am pretty sure the ratio between my chess.com and my OTB rating is the same for everyone.

Unfortunately, this is an empty question. OTB tournament chess is not the same as online chess. It's like asking someone to predict how you will look at a D1 school based on pickup games. Basketball is basketball, but the referees, crowd, history, duration etc. factor in to a D1 game making the two very different. Tournament chess is similar.

It depends. You'll hear people say chess.com ratings are generally a few hundred above your OTB, but don't believe that. In general, yes because there are not many rated OTB tournaments compared to the amount you can play online. For me, my chess.com rating is higher than my USCF rating simply because I don't play many rated OTB tournaments because I just don't have the time, but I can consistently beat people higher rated than me in an OTB game because the "skill" is there, I just don't play enough to have a huge impact in my rating. So, it really depends on how much you play OTB tournaments.
I am 1400 online (actually 1380 but I just had a bad day in chess so I don't count that)