Write out each class you took, the grade you received and the number of credit hours the class was worth. For example, assume you took History 101 and received a B worth three credit hours.
Convert your letter grade to a number using your course catalog's conversion. At the University of Maryland, an A+, A or A- is worth 4, B+, B or B- is worth 3, C+, C or C- is worth 2, D+, D or D- is worth 1 and an F is worth 0. In the example, the B would be worth 3.
Multiply the credit hours by the number grade to calculate quality points. In the example, 3 times 3 equals 9 quality points.
Add together all the quality points for your classes and add together all your credits in your classes. In the example, assume you have 30 total quality points and 10 total credits.
Divide your total quality points by your total credit hours to calculate your GPA. In the example, 30 divided by 10 equals a GPA of 3.