Write down each course, the number of credits and your grade. For example, you might write:
English 101, 3 credits, B+
Survey of American History, 4 credits, A
Swimming, 1 credit, A
Philosophy of the Middle Ages, 4 credits, B
Convert the grades to numbers. A = 4, B = 3, C = 2, D = 1, F = 0. A "+" adds 0.3 and a "-" subtracts 0.3, so a B+ = 3 + 0.3 = 3.3.
In our example:
English 101 = 3.3
Survey of American History = 4
Swimming = 4
Philosophy of the Middle Ages = 3
Multiply the credits by the numerical grade. In our example:
3 x 3.3 = 9.9
4 x 4 = 16
1 x 4 = 4
4 x 3 = 12
Add up the results in step 3. In our example 9.9 + 16 + 4 + 12 = 41.9
Add up the number of credits. In our example: 3 + 4 + 1 + 4 = 13.
Divide the result in step 4 by the result in step 5. This is your GPA. In our example: 41.9/13 = 3.22.