How grades are calculated depends on your teacher's weighting system
Your final grade is not usually an average of every score you earned. Instead, your teacher assigns different weights to different categories—homework might count for 20 percent, quizzes for 30 percent, and the final exam for 50 percent. Your grade is the sum of what you earned in each category, multiplied by its weight. If you know these weights and your scores, you can calculate your grade yourself before your teacher posts it.
The first step is finding your teacher's grading breakdown. This is usually in the syllabus, the course website, or a document your teacher handed out on the first day. If you cannot find it, ask your teacher directly—they should tell you what percentage each assignment type counts toward your final grade.
Key Takeaways
- Your final grade is a weighted average, not a straightforward average of all your scores, because different assignments count for different percentages.
- You need three pieces of information to calculate your grade: your scores in each category, the weight of each category, and the grading scale your school uses to convert numbers to letter grades.
- The calculation is: (score in category × weight) + (score in category × weight), repeated for each category, then added together.
- Your school's grading scale determines whether an 89 is an A or a B, so check your handbook or ask your teacher which scale applies.
Finding your scores in each category
Before you can calculate, you need to know your average in each graded category. If your teacher uses a learning management system like Canvas, Google Classroom, Schoology, or Blackboard, log in and look for a "Grades" tab. These systems usually show your score on each assignment and calculate category averages for you automatically.
If your teacher does not use a system like this, collect your graded assignments and calculate the average yourself. Add up all your scores in one category (for example, all homework scores), then divide by the number of assignments. That is your category average. Repeat for each category.
Write down your category averages clearly. You will need them in the next step.
Multiplying each category average by its weight
Once you have your category averages, multiply each one by its weight as a decimal. If homework is worth 20 percent, convert that to 0.20 and multiply your homework average by 0.20. If quizzes are worth 30 percent, multiply your quiz average by 0.30. Do this for every category.
Here is a concrete example. Say your grades break down like this:
| Category | Your Average | Weight | Weight as Decimal | Calculation |
|---|---|---|---|---|
| Homework | 92 | 20% | 0.20 | 92 × 0.20 = 18.4 |
| Quizzes | 85 | 30% | 0.30 | 85 × 0.30 = 25.5 |
| Final Exam | 78 | 50% | 0.50 | 78 × 0.50 = 39 |
The weights should always add up to 100 percent (or 1.0 as a decimal). If they do not, something is missing from your teacher's breakdown.
Adding the weighted scores to get your final grade
Add all the numbers you calculated in the previous step. In the example above: 18.4 + 25.5 + 39 = 82.9. That is your final grade as a number.
Your teacher may round this to 83, or they may keep the decimal. Either way, this is your grade before it is converted to a letter.
Converting your number grade to a letter grade
Schools use different grading scales, so an 83 might be an A at one school and a B at another. Check your school handbook, your teacher's syllabus, or ask your teacher which scale applies. A common scale is:
| Letter Grade | Number Range |
|---|---|
| A | 90–100 |
| B | 80–89 |
| C | 70–79 |
| D | 60–69 |
| F | Below 60 |
Using this scale, an 82.9 would be a B. But your school may use a different scale—some have 93 as the cutoff for an A, or 85 as the cutoff for a B. Always check before you assume.
What to do if your teacher uses a different system
Some teachers use point-based grading instead of percentages. In this system, each assignment is worth a certain number of points, and your grade is the total points you earned divided by the total points possible. For example, if homework is worth 100 points total and you earned 92, quizzes are worth 150 points and you earned 130, and the final exam is worth 250 points and you earned 195, your total is 92 + 130 + 195 = 417 points out of 100 + 150 + 250 = 500 possible. Your grade is 417 ÷ 500 = 0.834, or 83.4 percent.
Some teachers also use standards-based grading, where you are rated on whether you have mastered specific skills rather than earning a percentage. This system does not produce a number grade in the traditional sense. If your class uses this system, your teacher will explain how to read your progress report.
Using a calculator or spreadsheet to check your work
If you are working with several categories, a spreadsheet makes the math faster and less error-prone. Open Google Sheets, Excel, or any free spreadsheet tool. List your category names in one column, your averages in the next, and the weights in the third. In a fourth column, write a formula like =B2*C2 (where B2 is your homework average and C2 is its weight as a decimal). Copy that formula down for each category, then add all the results together.
You can also use an online grade calculator—search "grade calculator" and enter your scores and weights. These tools do the same math you would do by hand, so they are useful for double-checking but not necessary.
Frequently Asked Questions
Can I calculate my grade if I have not taken the final exam yet?
Yes. You can see what score you need on the final exam to reach a target grade. Work backward: subtract the weighted scores you already have from your target grade, then divide by the final exam's weight. For example, if you want an 85 and you already have 18.4 (homework) + 25.5 (quizzes) = 43.9, you need 85 − 43.9 = 41.1 from the final exam. Since the final is worth 50 percent (0.50), you need 41.1 ÷ 0.50 = 82.2 on the exam.
What if my teacher does not post all my grades yet?
Calculate with the scores you have. Your current grade will change as your teacher adds new assignments. If you want to estimate your final grade, assume you will earn a certain score on the assignments you have not done yet, then include those estimates in your calculation. Be realistic—do not assume you will get 100 on everything.
Does extra credit change how I calculate my grade?
Extra credit usually adds points to one of your categories (often homework or participation). Add those points to the category total before you calculate the average for that category. For example, if you earned 92 on homework and 5 extra credit points, your homework total is 97 before you divide by the number of assignments.
What if the weights do not add up to 100 percent?
Ask your teacher. This usually means you are missing part of the grading breakdown, or your teacher has not finalized the weights yet. Do not guess—the weights must add to 100 percent for the calculation to work.