Grades are "school specific* (so no one here can give you a straight answer to your last question). Your son’s GPA won’t be compared with some other kid’s GPA calculated with a different method; at least it won’t without some sort of conversion done by the college, which no one knows if they do or how they do it. And, whether the grading system is “fair” or “unfair” is a factor you have no control over right? Do you have any say to change the grading system of your son’s or the other schools’ grading system? Just let your son do his best. HIs current grades are stellar obviously and there’s not much room to get higher. The challenge is to keep up at a high level throughout his high school career while taking the most rigorous classes.