Actually what I was talking about is Surveybot's rating estimate.
Surveybot lets people submit their FIDE ratings, then compares it to their FICS rating. So anytime you type 'Tell Surveybot rating estimate FIDE' (or something like that) it will give you the result of its data. Obviously though many people on FICS are pretty stupid and care so much about having a high rating that they would lie even to a robot to make themselves feel better.
So I don't trust it precisely (my FICS rating is something like 1697 and it gave me a FIDE estimate of 1825 or something which is probably too high). But because I don't have a FIDE rating I can't judge whether it is accurate or not, which is why I wondered if other people would try it out and let me know!