The 4.0 point scale for Grade Point Averages is a common standard for recording and comparing student achievement. This article explains how to calculate a weighted grade point average or an unweighted gpa.
A Grade Point Average is one way of summarizing a student's performance as a single number. In a broad sense,
it is an average of the grades a student has achieved in all her courses of study. Grade Point Averages are used as a way for educational institutions to compare the results of students from different schools.
Grade Point Averages
There are different ways of calculating a Grade Point Average with secondary and tertiary schools using different methods. Generally secondary schools, such as High Schools use a direct average of the grades a student has achieved, while tertiary institutions such as universities also take into account the credit points associated with each course when calculating the average.
This article is a look at how to calculate Grade Point Averages (GPA) in a secondary environment such as High School. Internationally there is variation in the way different provinces or districts measure and record student performance, but the 4.0 point scale for calculating a GPA is becoming one widely used standard. For High School students the simplest way that you can calculate a GPA is as follows.
The Mathematics
Firstly each grade is assigned a numerical value. For example using the common set of letter grades of A, B, C, D, and F the value of each grade is:
A = 4.0
B = 3.0
C = 2.0
D = 1.0
F = 0.0
Your school may use different grades and values, but the method used to figure out the GPA will be the same in each case. Calculating the GPA requires totaling the value of the grades and then dividing by the number of grades. This results in an average that ranges between 0 and 4.0. With 4.0 been the highest GPA and 0 the lowest.
Unweighted GPA
Here is a concrete example. Student Michel has achieved these grades A, B, A, A, C, B, A, and A for the semester. Converting those grades to the numerical values they become 4.0, 3.0, 4.0, 4.0, 2.0, 3.0, 4.0, and 4.0. Adding these up (4.0 + 3.0 + 4.0 + 4.0 + 2.0 + 3.0 + 4.0 + 4.0) equals 28. Now to get the average the total is divided by the number of grades, which is 8, and the average becomes (28 / 8) which equals 3.5. So the GPA for Michel is 3.5.
The steps in this calculation are straightforward and easy to do, but if you need to calculate the GPA for a large set of students then a computer application is recommended to save time and reduce errors. With a spreadsheet you can set up the calculations, or to save more time a specialised application such as The Gradebook Program can convert letter grades to a final GPA in a single action.
A complication to consider is how the Grade Point Average is calculated if there are courses that work at an accelerated or higher level. For example, schools may have courses that are at an Advanced Placement, International Baccalaureate, or Honors level. When calculating the GPA, adjustments can be made so students in the more advanced courses receive a higher GPA.
Weighted GPA
When this is done it is called a weighted GPA. Continuing with Michel's example with the same list of grades, if the first three grades are from Advanced Placement (AP) courses, when those three grades are converted to a numerical value they are increased by a pre-determined amount to increase the students average.
By doing this a weighted GPA takes into account that an "A" in an AP course should reflect a higher level of achievement than an "A" in a regular course. And so students are rewarded for doing the more difficult study. Since this is called a weighted GPA, a GPA that does not take into account the level of the courses is called an unweighted GPA.
The amount that each grade is increased by will vary across schools, but for this example the AP courses get an additional 0.20 added to each grade. This makes the values 4.2, 3.2, 4.2, 4.0, 2.0, 3.0, 4.0, and 4.0 because 0.2 has been added to the first three values. So the new weighted GPA is (4.2 + 3.2 + 4.2 + 4.0 + 2.0 + 3.0 + 4.0 + 4.0) / 8 which equals 3.58 when rounded to 2 decimal places. With The Gradebook Program there is the option of weighting the grades to a weight you specify, or you can let the program do an unweighted GPA.
