In the 4 point grading scale, a number is assigned to a specific letter grade. For example, an A+ is assigned a 4.333, an A is 4.0, an A- is a 3.667 and so forth. For B’s, C’s and D’s the scale works the same way respectively with the numbers 3, 2 and 1. So for an additional example, the letter grade of B would represent a 3.0 and a letter grade of C- would represent a 1.667.
The 4 point grading scale can also be used in conjunction with calculating a weighted grade point average. Consider that you are a student and have just completed a semester in college and have received your final letter grade for each class. You would likely want to determine your 4 point scale GPA for each class but also calculate your weighed grade point average for the semester. To do this you would simply assign the grading scale number to each letter grade for the class and then multiply this number by the number of credit hours for the class divided by the total number of credit hours for all classes taken. This term would be the weighted GPA term for each class, you would then add each of these terms to get your weighted semester grade point average. You can use this same method to calculate a cumulative GPA over several semesters by performing the same calculation for all classes taken and using the total number of class credit hours over this time.
A basic calculation will clarify this concept.
Say we want to determine the semester weighted grade point average for the following classes taken and completed.
Algebra II: B (4 credit hours)
Intro to Biology: B+ (3 credit hours)
Creative Writing: A- (3 credit hours)
Early European history: A (3 credit hours)
Economics 101: C (4 credit hours)
So let’s assign the 4 point scale number to each letter grade.
Algebra II: 3.0
Intro to Biology: 3.333
Creative Writing: 3.667
Early European history: 4.0
Economics 101: 2.0
We see that the total number of class credit hours is 17 and with this we can now find the weighted GPA term for each class as follows.
Algebra II: (3.0)(4/17) = 0.706
Intro to Biology: (3.333)(3/17) = 0.588
Creative Writing: (3.667)(3/17) = 0.647
Early European history: (4.0)(3/17) = 0.706
Economics 101: (2.0)(4/17) = 0.471
So now we can determine the final, semester weighted grade point average.
GPASEM = 0.706 + 0.588 + 0.647 + 0.706 + 0.471
GPASEM = 3.12 (A little bit better than a B)