I don't think they have such a function at this time. I know it has been discussed a few times in a few threads, but I don't think they intend to add such a funciton.
There definitely was such a calculation discussed in the forums a few months ago. I don't think it was very accurate though. I'm afraid I don't know where to find it.
Ugh, I don't like it. The numbers it returns are too high ; )
A bit of digging led me to find the thread that appears to have spawned the site A little bit of math never hurt anybody althought the maths behind it has changed somwhat from what was posted there.
Bod, I agree. I think the math has changed. It'll give you a rough approximation. I wish it was right 100% ot the time, though; it is predicting that I will take first place at 7.24 on the cliché challenge. I'll be lucky if I get a ribbon. Scores have been higher as of late.