Some GPAs are calculated by adding the amount of earned points in a class. Each assignment or test is awarded points. For example, a test may be worth 100 points, a quiz 20, and writing assignments 25. Usually in this type of system there will be more than 100 points to be earned in the class. When all the points are tabulated at the end of the semester, they could equal 1,000 points or more. If a student wants to determine his GPA expressed as a percentage, he divides the total number of points earned by the number of points possible and multiplies the answer by 100. This same formula can be used in tabulating total GPA from multiple point-system classes.
Number GPAs are a little easier to calculate. Usually the grades are out of 100 points for all assignments, and the student simply has to add the grades together and divide by the number of grades added. This same strategy also works for figuring out total GPA for a number of classes, because all the graded classes are weighted the same.
Instead of numbers or points, some schools assign letter grades. Usually there is a number range associated with the letter. For example, in some schools a letter grade of "A" is assigned to a numerical GPA of 90 or above. Some schools also add + or - to the letter grade, indicating where that student fell in the range assigned to the letter. For example, an "A+" may indicate a student has a numerical GPA of 95 or better. Different schools assign different number ranges to their letter grades, so it is important to use the correct range scale.
Some schools assign grades on a 4.0 scale. Anytime a student receives a 90 or above in a class, they are awarded a GPA of 4.0. If the student gets an 89 or less in a class, the 4.0 will drop to match the grades. For example, a 3.3 GPA could mean the student has around an 85 average. When using the 4.0 scale, it is important to look at the correctly assigned grade scale set by the school. For determining GPA from several classes, divide the added grade points by the total class credits attempted. Some schools divide the grade points by the total class credits earned.