How to Calculate Grades Based on Percentages (With Calculator!)

Many high school teachers and college professors weigh homework, quizzes and test grades differently depending on the difficulty and significance of the assignment. Big tests (like a midterm exam or final exam) and quizzes generally account for most of the total grade, because they encompass more of the subject material.

The letter grades you receive in the gradebook after all of your individual assignments, tests, and quizzes have been graded make up your grade point average (gpa). Typically, students want to keep their gpa as high as possible. Whether you are on the verge of failing a class, or you have pretty good grades and just want to know how your grades add up, you can calculate your grades with a few simple formulas.

Determine Grading Policy

1. establish your professor's grading policy for how each category is weighted.

The professor may announce this early on in the class for clarity. If they do not, you can also check with the course syllabus or refer to the school policy.
Asking directly may be best because of professor preferences in their weighted grading system that may not be updated in online materials.

For example

The professor may weigh 35 percent of the final grade to quizzes, 20 percent to homework and 45 percent to tests.

Grade Calculator

Below we provide a grade calculator as an alternative to performing the grade calculations explained in the article.

Calculate Category Averages

2. Calculate the average of each category by adding up all of your scores for each category and divide by the number of assignments in that category.

For example

If you have five tests with the scores of 90, 85, 100, 75 and 91, the accumulated point total for all your test would be 441. Divide the total by five for your test average of 88.2 percent.

Converted Weighted Grade Percentages

3. Convert the weighted grade percentages to decimal value by dividing the percentage by 100.

For example

If tests are weighted 45 percent of the total grade, the decimal would be 0.45 (45 / 100 = 0.45).

Repeat this step for each weighted section (homework, quizzes, tests, etc.).

Calculate Averages

4. Multiply the average for each category by the weight, in decimal, of each category to calculate the total points out of 100.

For example

If your test average is 88.2 percent and is weighted 45 percent, the points for your overall grade out of 100 would be 39.69 (which is 88.2 x 0.45). Repeat this step for your other subject categories.

While most professors will maintain the final grade given, speaking with the professor can result in updating the grade through additional projects or corrections.

Additionally, if a student is not happy with the course grade, some colleges have policies allowing classes to be repeated and then averaged, which can also raise a course grade as well as your overall gpa.

Determine Total Grade

5. Add the results for each category from Step 4 to find out your total grade out of 100 points.

For example

If you calculated a 39.69 for test, 34 for quizzes and 18.5 for homework, your total grade would be 92.19 percent.

General 5 Letter Grade Score Table
A	90 - 100
B	80 - 90
C	70 - 80
D	60 - 70
F	Below 60

At many colleges using a four-point scale, an A requiring a total grade of 90 with a B letter grade falling in the 80 percent range.

A C grade ranges between 70 and 80 percent with a D ranging from 60 to 70 percent. Anything below a 60 percent would be considered a failing grade, or F.

These grade ranges do vary by school and professor, and they are general estimates with some colleges starting an A at 92 percent, a B at 83 percent and so on.

Detailed Numeric to Letter Grade Table
93-100	A
90-92	A-
87-89	B+
83-86	B
80-82	B-
77-79	C+
73-76	C
70-72	C-
67-69	D+
60-66	D
0-59	F

How to handle a weighted grading system?

A weighted score is the key to understanding where your professor wants you to focus. Look especially for attendance or term papers. If your syllabus mentions extra credit, do the extra credit work because it gives you a buffer going into your final exam.

How to handle point systems to determine your total score?

The key is to start from the max total score and follow the breakdown from tests and quizzes to homework and attendance.

As an example, a language course has a quiz every class that is worth 20 points. If you have 30 quizzes or two per week, the total quiz points is 600. If the total number of points is 1,000 and 600 or 60% (600 / 1000) comes from quizzes, you should spend extra time ensuring you maximize your quiz score.

On the other hand, point values from quizzes are often weighted lower than your midterm and final grades – often, because your instructor wants to grade you on your complete understanding of the material rather than recalling by rote something from the textbook.

How to determine how much you need to score on your final exam to maintain your grade?

Your overall grade will often be determined by your final exam. Because your class is almost complete, you should take your syllabus and your scores and be able to calculate your current class grade.

For example, your current grade may be a B+ because out of 800 possible points, you have 704 points or 88% (704 / 800). If your final exam is worth 200 points, then your total points is 1,000 and you will need 186 on your final exam for an A- (900 / 1000 is 90%) and a perfect score on your final exam worth 200 points, will still keep you at an A- for your overall grade. Why? Because your final exam was only 20% of your total grade.