Your turn-based rated (correspondence chess or CC rating) is usually 200-500 points higher than a USCF OTB rating... I might say 300 is a good average.
The live chess on here is closer, probably +-100 points for most people.
Things like how seriously you take the games, how many games you play at once, how heavily you lean on the analysis board or databases. In live chess how often do you play 1/0 to win on time, how often do you try risky attacks or fun gambit openings you'd never play OTB etc can affect how big the difference is for you.
I've played a few games on here and am probably going to start going to a club soon, but I'm wondering what my rating translates to in OTB strength. I realize it's an inexact question, as my play here is correspondence-style, and ratings vary across organizations anyway (USCF vs. FIDE, for instance), but speaking generally, how can someone estimate their OTB rating from their Chess.com rating?