A weighted grade point average (GPA) adjusts for differences in class difficulty, while an unweighted GPA does not. A weighted GPA counts more difficult classes more heavily in calculating the overall GPA.
Some students try to increase their overall GPA by taking easier classes, especially elective classes that are not part of the core curriculum. Some schools present a weighted GPA in addition to an unweighted GPA to distinguish between students who get a high GPA by taking easy classes and students who get a high GPA by taking more challenging classes.
For example, consider two students, Jack and Jill, who both get a 4.0 in Social Studies, a 3.6 in English, a 3.2 in Science and a 3.0 in Math. But Jill takes all Honors classes, while Jack takes only Regular classes. Their unweighted GPA is the same, a 3.45 on a 4.0 scale. But, since Jill took more difficult classes, her weighted GPA is a 3.95 on a 4.0 scale, while Jack’s weighted GPA is the same as his unweighted GPA.
Neither a weighted GPA nor unweighted GPA is comparable between schools, since each school may have different grading standards and offer classes with different levels of difficulty. Also, each school’s weighting methodology may differ.
Instead, colleges prefer to review detailed high school transcripts to determine whether the student took challenging classes and to evaluate the student’s academic performance in core college prep classes.
Ultimately, each college uses the student’s high school grades, transcripts and admissions test scores to predict the student’s academic performance at the college. They develop detailed predictive models based on data from previous students from the same high school who enrolled in the college. These models can be used to predict the college GPA for students from each high school and whether the students will graduate.