The principles of the rating system are the same (200 point rating difference means 75% probablity of win by higher rated player, for example.)
However, ELO and BCF ratings are based on over-the-board (OTB) play, whereas this is a correspondence chess site, so different types of chess skills come into play and the two types of ratings are not comparable. If you do well under time pressure, your ELO rating should be higher than your rating here; if you like time to think, or find the analysis board essential, it should be the other way around.
Another factor is that the absolute level of ratings may be different. People start here with a 1200 rating. I don't know what a typical starting rating is for someone who joins a chess club at school or elsewhere.
It would be interesting to hear from some of the players here who have OTB ratings as to how RHP ratings compare.