How to convert percentage scores to the GPA 4.0 scale

Converting a score or a set of scores into a percentage according to the GPA 4.0 scale can be somewhat tricky. Here are some simple methods to clarify how a percentage is accurately converted into a GPA score based on the 4.0 scale.

Know the formula to convert a percentage to a GPA on the 4.0 scale. Let x represent the percentage. The formula for converting percentage to GPA (on the 4.0 scale) is (x/20) - 1 = GPA.

Insert the percentage into the formula and calculate. For instance, if you scored 89% in Geology, simply plug that percentage into the formula, and you get:

• 89/20 - 1 =
• 4.45 - 1 = 3.45.
• The GPA equivalent for 89% is 3.45.

Use a similar formula if the percentage is over 100%. The process remains the same even if your percentage exceeds 100%. For example, if you scored 108% in Algebra, here's how you'd calculate:

• 108/20 - 1 =
• 5.4 - 1 = 4.4
• The GPA equivalent for 108% is 4.4.

Consider using a grading scale. This can be helpful depending on the purpose of calculating your GPA. If you are determining your GPA for a specific class to understand how it will contribute to your overall GPA in high school, you don't necessarily need to follow the exact formula, as all scores fall within a range. For instance, if your score is between 83-86, you may receive a B or a 3.0 depending on the high school, and this score may either be above or below the cutoff.

• Check the GPA calculation system of your school to understand how they grade; some schools have different grading ranges to determine A-, A, B, B+, and other grades.

Assign each grade you earn in each class a corresponding GPA score. Each grade you receive at the end of a course is matched with a number on the 4.0 scale. The grading system may vary slightly between schools, so it’s important to check your school’s GPA system. Here's a typical conversion chart:

• A = 4
• A- = 3.7
• B+ = 3.3
• B = 3
• B- = 2.7
• C+ = 2.3
• C = 2.0
• C- = 1.7
• D+ = 1.3
• D = 1
• D- = .7
• F = 0

Add up all your scores. Sum the scores assigned to each letter grade from your classes. For example, if you earned a (C+) in English, a (B) in History, a (B+) in Math, a (C+) in Chemistry, an (A-) in Physical Education, and an (A-) in Art, your scores would be: 2.3 + 3 + 3.3 + 2.3 + 3.7 + 3.7 = 18.3.

Divide the total score by the number of classes you attended. This is another method for calculating your average GPA. It helps determine your final GPA on the 4.0 scale.

• Using the example above, the total score is 18.3. Since you took 6 classes, divide 18.3 by 6, which gives: 18.3 ÷ 6 = 3.05 (rounded to 3.1).

Understand weighted GPA (GPA for special classes). Weighted GPA is used for more challenging classes, such as honors or AP (Advanced Placement) courses. This system reflects the increased difficulty of these classes. Therefore, instead of the traditional 4.0 scale, the scale for special classes may go up to 5.0, indicating a more demanding curriculum. For example, getting a "C" in an AP Algebra class is equivalent to getting a "B" in a regular Algebra class.

Assign grades to letter grades in each class. This time, use the same conversion chart as before, but add 1 point to each grade earned in an honors or AP class. Below is a common grading system:

• A = 5
• A- = 4.7
• B+ = 4.3
• B = 4
• B- = 3.7
• C+ = 3.3
• C = 3.0
• C- = 2.7
• D+ = 2.3
• D = 2
• D- = 1.7
• F = 1

Sum up all your scores. Add the scores assigned to each letter grade you earned in each class. For example, if you got a (C) in AP English, a (B) in Honors History, a (B) in Math, a (C+) in AP Chemistry, a (B-) in Music Theory, and an (A-) in Honors Art, your total would be: 3 + 4 + 3 + 3.3 + 2.7 + 4.7 = 20.7.

Divide your total score by the number of classes you attended. Remember, you are just calculating the average. This helps determine your final GPA on the 5.0 scale. Note that the 5.0 scale applies only if all your classes are either honors or AP classes and you score "A" in each of them. Many students are required to take certain classes without a higher difficulty level, such as physical education.

• Using the example above, the total score is 20.7. Since you attended 6 classes, divide 20.7 by 6. You get: 20.7 ÷ 6 = 3.45 (rounded to ).

Multiply the credit hours by the corresponding letter grade for each class (see image below) to get your Quality Points.

• Example: (3 Credit Hours * 4.5 (A+))

Divide the total Quality Points by the total number of credits.

• Formula: (Credit hours * grade points) / (Total credits); or
• (Quality Points) / (Total credits)

Complete. This represents your GPA.

• GPA / 4.0 = X / 4.5

• If preferred, use a calculator to solve the equation for a quicker and simpler result.