Ask your professors for your current grades. You need your grades from each class to accurately calculate your GPA.
Apply a numeric grade to each of your letter grades using the standard GPA conversions:
A = 4 points
B = 3
C = 2
D = 1
F = 0
Add together the points for each letter grade. With one "C" two "B"s and three "A"s you have a total of 20 points in six classes.
Divide your numerical value by the number of classes in which you are enrolled. Using this example you will divide 20 by six classes for a GPA of 3.3.