Rating Formula?

I've been looking around the forums for a little while and I can't seem to find the formula to find a rating. Would anyone happen to know it and would care to share?

Btw I know there are rating calculators online but they are fairly limited and I'd like that chalenge of making my own:)

Try:

http://istaria.wikia.com/wiki/Genera...ing_Guidelines

Knossos

Awesome. And it works:) 28 Adv classes at lvl 100 is 278:) so thank ya much knossos

Sir knows it all:):)
*bows to him and his knowledge*