It's the class average GPA of that listed on the application. But it all works out in the wash. Some people's gpa goes up after admissions re-weights them. Some go down. Some stay the same as their high school. I've seen all of them. FWIW: My son had a 4.0gpa in high school. He was in the IB program. All his classes were IB. He was in the program all 4 years of high school. (Our state starts high school in 9th grade if you're in the IB program). He was class ranked #1. The school doesn't weight classes and GPA. But they do weight class ranking, so a 4.0gpa IB student is higher than a 4.0gpa state minimum curriculum. Anyway; his GPA stayed the same with the academy. It didn't move at all. But that has to do also with the school profile and such. IB is probably the most "Standard" of academics in the country. Actually, it's standardized world wide. But some times even an IB student will have their gpa weighted by the academy depending on their electives and the school profile.
Anyway; that's how they determine the "Class GPA". It's after the academy weights them. And again, it all washes out in the mix. So the class gpa is still very close to even an unweighted class. mike....
P.S. On your application; the part you DON'T SEE; part of your WCS (Your TOTAL score on EVERYTHING in your application), there is a section they grade you on for academics. You get scored on ALL your academics. You get "X" amount of points for your GPA, "Y" for your SAT/ACT, "Z" for the difficulty of classes; e.g. IB, AP, Honors; "W" for class rank; etc.... So there's a lot more to it than saying one person had a 3.9 gpa, one had a 4.0, and another had a 3.8. One may appear to be much better than another, but they really aren't in the scoring process. Where you "GAIN" or "LOSE" a lot of points is on the "Difficulty Level" of the classes you DID take vs the "Difficulty Level" of the classes available to you. I.e. They will NOT penalize an applicant who didn't take IB or AP or Honors classes if they or that program wasn't available to them. However; they WILL penalize you if such classes were available, and you didn't take them. In other words, a 3.8 gpa IB applicant will most likely get more academic points than a 3.95 gpa applicant who didn't take IB/AP classes and they WERE available at their school. But again, there's also a mixture of the SAT/ACT, ranking, school profile, difficulty, etc....