Calculate class percentage if you have not yet received grades from your courses. Take the points you have received in the course and divide it by the total points possible, then multiply that number by 100. For example, if you received 900 points out of 1,000 possible points, divide 900 by 1,000 to get .90 and multiply that by 100. You would have 90 percent in the class.
Convert your class percentage into a letter grade.
Change the letter grades to a number in the 4-point GPA system. For example, A = 4 points; B = 3 points; C = 2 points; D = 1 point and F = 0 points.
Determine the number of units for each class and multiply that number by the points you received. For example, if you are taking a 3-unit class and received a "C" grade (2 points), you would multiply 2 by 3, which equals 6. Repeat this process for each of your classes.
Find your total grade points by adding each of your classes' points together. You should also determine how many total units you attempted. Your total grade points should be divided by the total units. For example, if you took four, 3-unit courses and received three "B" grades and one "C" grade, your total grade points would equal 33. Divide this number by the total units (12). Your GPA will equal 2.75.