D19 has stated in the Commom App that her school’s grading scale goes up to a 5, but students can only have higher than a 4.0 with weighted classes. Based on that, I told her the scale caps out at 4. Who’s right?
The school profile states the max GPA for non weighted is 4.0, but also explains the AP/dual weight added.
For Common App purposes, if an unweighted A = 4.0, then the unweighted grading scale for the school is 4. If a weighted A = 5.0, then the grading scale is 5. On the CA, one has to indicate the grading scale and if the scale is weighted or unweighted. If the transcript reflects both, then the weighted option should be chosen.
https://appsupport.commonapp.org/applicantsupport/s/article/What-should-I-list-for-our-school-s-GPA-scale
https://appsupport.commonapp.org/applicantsupport/s/article/How-do-I-report-my-class-rank-and-GPA
@skieurope Thank you for that information. I’m still somewhat confused, though. The highest possible GPA is not a 5.0 because it’s not possible to take all weighted classes. If a straight A student with several AP classes has a 4.4 and says the scale is 5.0, doesn’t it look like they have a low GPA?
As I said, my explanation was simply as it relates to the Common App, which was how you led off your question.
Excluding how to fill out the Common App, in my example, the grading scale is fixed at 4. So a student with a 4.4 weighted GPA is still on a 4.0 scale.
The reality at the end of the day is that the question is one of those “angels on a head of a pin” things that nobody cares about other than the one asking. 
When she’s old enough, pour both of yourselves a glass of wine and debate it.
Well, even the Common App’s explanation isn’t all that clear:
“If your school uses a weighted GPA, you should list the highest possible weighted grade average a student can achieve and select the weighted option in the GPA Weighting prompt.”
Who knows what’s the highest possible weighted GPA is if most students have a combination of weighted and unweighted classes? Anyway, she’s going to say the scale is 4. I need the wine NOW! ?
That is a pretty typical high school grading system. 4.0 is UW and is the highest GPA you can get UW. Classes that are weighted are can bring it up over a 4.0.
It’s using the standard of the highest possible grade for a particular course. So if a school adds 1.0 for AP/IB and 0.5 for honors, the weighted GPA scale is 5.0. It’s not asking "what is the highest GPA a student can achieve, which will be less than 5.0 since you can’t take all AP classes.
That said, if a student misinterprets the wording, a college will not ding the applicant. A huge chunk of kids screw up this question every year.