Calculate your GPA regularly to see where you stand. For example, you have a 2.5 after your first semester in college and you took four classes. To raise your cumulative GPA to a 3.0 in one semester you have to take a minimum of four classes and earn at least two As and two Bs.You can calculate this by using the GPA conversion, which provides numerical value to letter grades. A = 4 points. B = 3 points.C = 2 points. D = 1 point. Give each of your grades a numerical value, add the numerical values and divide them by the number of classes you are taking.alculate your GPA regularly to see where you stand. For example, you have a 2.5 after your first semester in college and you took four classes. To raise your cumulative GPA to a 3.0 in one semester you have to take a minimum of four classes and earn at least two As and two Bs.