How to Calculate Exam Grades After a Test
By Per Thoresson
Calculating an exam grade is simple when the test is worth a certain number of points. It gets more confusing when the exam is weighted, curved, or only one part of your overall course grade.
This guide walks through the common formulas so you can answer three questions:
- What percentage did I get on the exam?
- How does this exam affect my course grade?
- What do I need on the next exam or final?
Key Takeaways
- Exam percentage = points earned divided by points possible, multiplied by 100
- Weighted grades depend on how much the exam counts toward the course
- A high-weight exam can move your average dramatically
- Always use the weights from your syllabus
- Use a calculator if you are solving for the score you need on a future final
How to Calculate a Basic Exam Grade
Use this formula:
Exam grade = (points earned / points possible) x 100
Example:
You scored 42 out of 50.
42 / 50 = 0.84
0.84 x 100 = 84%
Your exam grade is 84%.
This works for any point-based test:
| Score | Calculation | Grade |
|---|---|---|
| 18/20 | 18 / 20 x 100 | 90% |
| 37/45 | 37 / 45 x 100 | 82.2% |
| 76/100 | 76 / 100 x 100 | 76% |
How to Calculate a Weighted Exam Grade
A weighted exam grade means the exam counts for a specific percentage of your course grade.
Example:
- Homework: 20%
- Midterm: 30%
- Final exam: 50%
If you scored 84% on the midterm, and the midterm is worth 30% of the course, its contribution is:
84 x 0.30 = 25.2
That exam contributes 25.2 percentage points toward your final course grade.
How to Calculate Your Current Course Grade
Use this formula:
Course grade = sum(each grade x its weight)
Example:
| Category | Grade | Weight | Contribution |
|---|---|---|---|
| Homework | 92% | 20% | 18.4 |
| Quiz average | 80% | 20% | 16.0 |
| Midterm | 84% | 30% | 25.2 |
| Final | Not taken | 30% | ? |
Your completed work so far contributes:
18.4 + 16.0 + 25.2 = 59.6
But because the final is not taken yet, you do not have the full course grade. You have 59.6 points out of the 70% that has been graded.
Your current average on completed work is:
59.6 / 0.70 = 85.1%
How to Calculate What an Exam Did to Your Grade
Suppose your current course grade before the exam was 90%, and the exam is worth 25% of the course. You scored 76%.
Your new grade:
Old work: 90 x 0.75 = 67.5
Exam: 76 x 0.25 = 19.0
New grade: 67.5 + 19.0 = 86.5%
The exam lowered your average from 90% to 86.5%.
This is why exam weight matters. A 76% on a quiz worth 5% barely moves the grade. A 76% on a final worth 45% can change everything.
How to Calculate What You Need on the Final
If you want to solve for a future final exam score, use the final grade calculator. It does the weighted average algebra for you.
The formula is:
Needed final score = (target grade - current contribution) / final weight
Example:
- Current contribution from completed work: 58 points
- Final is worth 30%
- Target course grade: 80%
(80 - 58) / 0.30 = 73.3
You need about 73.3% on the final to finish with 80%.
What If the Exam Is Curved?
A curve changes how raw scores convert into grades.
There are different kinds of curves:
- Adding points to everyone
- Scaling the highest score to 100%
- Assigning letter grades by class distribution
- Dropping bad questions
If the exam is curved, calculate your raw percentage first, then wait for the adjusted grade from your instructor. Do not assume every curve works the same way.
What If the Syllabus Uses Categories?
Some courses do not weight each exam individually. They use categories.
Example:
- Exams: 60%
- Homework: 25%
- Participation: 15%
If there are three exams inside the exam category, first calculate the exam category average. Then multiply that average by the category weight.
Example:
| Exam | Score |
|---|---|
| Exam 1 | 80% |
| Exam 2 | 86% |
| Exam 3 | 90% |
Exam average:
(80 + 86 + 90) / 3 = 85.3%
Exam category contribution:
85.3 x 0.60 = 51.2
Common Grade Calculation Mistakes
Using points when the class uses weights. A 20-point quiz and a 100-point exam may not matter according to point totals if the syllabus uses weighted categories.
Forgetting ungraded work. Your current grade may look high because the final has not been counted yet.
Mixing percentages and decimals. Use 30% as 0.30 in formulas.
Assuming the final replaces a previous exam. Some courses replace the lowest exam grade with the final, but many do not. Check the syllabus.
Ignoring dropped scores. If the lowest quiz is dropped, calculate after applying that rule.
How to Raise Your Grade After a Bad Exam
First, calculate the damage accurately. Then decide what still has enough weight to matter.
If the remaining final is worth a lot, build a focused plan:
- Review every wrong answer
- Identify repeated mistakes
- Generate practice questions from weak topics
- Use flashcards for definitions and formulas
- Take at least one timed practice test
The AI quiz generator can help if you do not have practice questions, and the guide on reviewing wrong answers can help you avoid repeating the same mistakes.
Frequently Asked Questions
How do I calculate my test grade?
Divide points earned by points possible, then multiply by 100. For example, 45 out of 60 is 75%.
How do I calculate weighted exam grades?
Multiply the exam score by its course weight. An 85% exam worth 30% contributes 25.5 points to the final grade.
How do I know what I need on my final?
Use the final grade calculator or the formula: target grade minus current contribution, divided by final exam weight.
Why did my grade drop so much after one test?
The exam was probably heavily weighted, or there are not many other grades in the course yet. High-weight exams move the average more.
The Bottom Line
Basic exam grade math is points earned divided by points possible. Course grade math depends on weights.
If you are trying to figure out what you need next, use the free final grade calculator. Then turn the result into a study plan with practice questions, flashcards, and wrong-answer review.