An index score is calculated by multiplying your LSAT by some constant number, multiplying your GPA by some other constant number, adding those together, and adding another constant number to them. LSAC has the formulas for schools that choose to release their index formulas. Go to
www.lsac.org, click on the Online Services tab, click on the MyDocs tab, click on Transcripts, and then click on the Admissions Index .pdf file.
Of 8 schools I plan on applying to this fall, only 4 of them released their formulas. After you figure out your index score, it's meaningless unless you know what the average was at that school. For that, refer to
www.lawschoolnumbers.com. I tried e-mailing each of those 4 schools to ask what they do with the index scores, and they all claimed not to use it for anything meaningful. I heard from my TestMasters LSAT instructor that some schools use it as follows: above a certain index score, and you're almost guaranteed admission, below a certain index score, and you're almost guaranteed rejection. And everything else is in the middle ground and needs to be evaluated more closely. Obviously none of the schools confirmed that to me, but it's certainly a possibility.
Hope that helps!
