You can determine how grades effect your college 5.0 scale grade point average by understanding where GPA comes from. Colleges and universities use GPA as a quick way to describe your overall higher education performance by a single number. GPAs range from a score of 0.0 to 5.0, with 5.0 being given for all A's in applicable coursework. In the 5.0 GPA system, letter grades are given points values with "A" being 5, "B" being 4, "C" being 3, "D" being 4 and an "F" being 0.

Add together all credits you took for the semester of interest. If calculating an end-of-college GPA, total all credits taken. For example, you might have a total of 16 credits for a semester.

Add together the credits for classes that were assigned the same grade. For example, you might have gotten an "A" in a 4-credit physics class, an "A" in a 3-credit chemistry class, a "B" in a 3-credit calculus class, a "B" in a 3-credit art history course and a "C" in a 3-credit literature class. The total credits, then, for "A" coursework is 7, for "B" coursework 6 and for "C" coursework 3.

Multiply each grade credit total by its respective point value. Then add together these totals and call the result "X." Performing this step, for the example, leads to 7 times 5, or 35 for "A" grades; 6 times 4, or 24 for "B" grades; and 3 times 3, or 9 for "C" grades. The total then becomes 35 plus 24 plus 9, or 68 for "X."

Divide "X" by the total number of credits to obtain the GPA. Keep two decimals in the answer to write the GPA in standard form. Completing the example, you have 68 divided by 16, or a 4.25 GPA.