Average GPA: 3.51. The average GPA at Trinity University is 3.51. This makes Trinity University Strongly Competitive for GPAs. (Most schools use a weighted GPA out of 4.0, though some report an unweighted GPA. With a GPA of 3.51, Trinity University requires you to be around average in your high school class. You'll need a mix of A's and B's, and very few C's. If you took some AP or IB classes, this will help boost your weighted GPA and show your ability to take college classes.