Cool idea, but how do you account for variations on what certain brands consider a 33-length, for example?
Like for example, 32-waist Wrangler seems to be equivalent to 30-waist Gap. Only way I know this is because I tried on the jeans at the mall and found those to be the most comfortable on me.
The variation is strange and it's not just pants but also shoes sizes aren't consistent between brands either. I think the way Zappos solves this is they send you the shoes and you send them back if they don't fit well.