Many classes do not count every assignment equally. A syllabus might say homework is 10% of your grade while the final exam is 30%. That is a weighted grade: each category counts in proportion to its weight. This guide shows how to calculate one by hand, step by step, with clear arithmetic you can copy for your own classes.
All scores below are made-up examples to show the math. Always use the weights from your own syllabus.
Why a simple average gives the wrong answer
Imagine a class with only two categories: homework worth 20% and exams worth 80%. You have 95% in homework and 70% in exams.
- Simple average: (95 + 70) ÷ 2 = 82.5%
- Weighted grade: 95 × 0.20 + 70 × 0.80 = 19 + 56 = 75%
The simple average treats both categories as equally important, but here exams count four times as much. The weighted grade, 75%, is what your teacher will use.
The weighted grade formula
- Weighted grade = (score₁ × weight₁ + score₂ × weight₂ + …) ÷ (sum of the weights)
Each "score" is your category average as a percentage; each "weight" is that category's share of the course. When everything is graded and the weights total 100%, the final division is just dividing by 1. It matters when some categories are still empty, as you will see below. Our weighted grades page has a short reference version of this formula.
Step-by-step: calculate a weighted grade
- Find the weights in your syllabus or class portal. Write them down exactly.
- Work out your average in each category, such as homework or quizzes.
- Convert each weight to a decimal by dividing by 100: 20% becomes 0.20.
- Multiply each category average by its decimal weight. This is the category's contribution.
- Add the contributions together.
- Divide by the total of the weights you used (as decimals). If all categories are graded and the weights total 100%, this is 1.
Worked example: a finished course
Here is a course where every category has a score:
| Category | Weight | Your average | Contribution |
|---|
| Homework | 10% | 92% | 92 × 0.10 = 9.2 |
| Quizzes | 20% | 85% | 85 × 0.20 = 17.0 |
| Projects | 20% | 90% | 90 × 0.20 = 18.0 |
| Midterm | 20% | 78% | 78 × 0.20 = 15.6 |
| Final exam | 30% | 84% | 84 × 0.30 = 25.2 |
Add the contributions: 9.2 + 17.0 + 18.0 + 15.6 + 25.2 = 85.0. The weights add up to 10 + 20 + 20 + 20 + 30 = 100%, so the weighted grade is 85.0%. On a common U.S. scale that is a B, but check your school's letter grade scale, because cutoffs vary.
Mid-semester: when some categories are not graded yet
Most of the time you want your grade before everything is finished. Suppose the projects and the final exam have not happened yet in the same course:
| Category | Weight | Your average | Contribution |
|---|
| Homework | 10% | 92% | 9.2 |
| Quizzes | 20% | 85% | 17.0 |
| Midterm | 20% | 78% | 15.6 |
- Contributions: 9.2 + 17.0 + 15.6 = 41.8
- Weights used so far: 0.10 + 0.20 + 0.20 = 0.50
- Current grade: 41.8 ÷ 0.50 = 83.6%
If you divided by 1 instead of 0.50, you would get 41.8%, which looks like a failing grade. It is not: you have simply only completed half of the weighted work. Leave ungraded categories out of both the top and the bottom of the formula. Do not enter them as zero unless you really scored zero.
Once you know your current grade, you can work out the score you need on the final. Our guide on what you need on your final walks through that formula.
How to get each category average right
The weighted formula is only as good as the category averages you feed it. If the assignments in a category are worth different numbers of points, add up the points instead of averaging the percentages.
Say your quiz category has a 10-point quiz where you scored 10, and a 50-point quiz where you scored 30.
- Averaging percentages: (100% + 60%) ÷ 2 = 80%
- Adding points: (10 + 30) ÷ (10 + 50) = 40 ÷ 60 ≈ 66.7%
Unless your teacher says each quiz counts equally, use the points method. See how to calculate grade percentage for more. Also check the grade FAQ if your teacher drops your lowest score or gives extra credit.
When the weights are not percentages
"Tests count double"
Some teachers describe weights as multipliers. If tests count twice as much as homework, give homework a weight of 1 and tests a weight of 2. With a homework average of 90% and a test average of 75%:
- (90 × 1 + 75 × 2) ÷ (1 + 2) = (90 + 150) ÷ 3 = 240 ÷ 3 = 80%
This is why the formula divides by the sum of the weights: it works whether weights are percentages, decimals or simple multipliers.
Total-points classes
Other classes list points instead of weights, for example homework 200 points, exams 600 points and a project 200 points, for 1,000 points in total. Here the weighting is built in, so you just divide total points earned by total points possible:
- Earned: 180 (homework) + 450 (exams) + 170 (project) = 800
- Grade: 800 ÷ 1,000 = 80%
You can check that it matches the weighted method. The categories are worth 20%, 60% and 20% of the points, and your category averages are 90%, 75% and 85%: 90 × 0.20 + 75 × 0.60 + 85 × 0.20 = 18 + 45 + 17 = 80%.
Which category should you focus on?
Raising a category average by 10 points changes your overall grade by 10 × that category's weight:
- Quizzes (20%): +10 points in quizzes = +2.0 points overall
- Homework (10%): +10 points in homework = +1.0 point overall
- Final exam (30%): +10 points on the final = +3.0 points overall
Heavily weighted categories move your grade the most, so plan your study time with that in mind.
Common mistakes
- Taking a simple average of the categories instead of weighting them
- Dividing by 100% while some categories are still empty
- Entering 0 for an assignment that has not been graded
- Averaging percentages when assignments have different point values
- Copying a weight wrong from the syllabus, so the weights do not add up to 100%
- Confusing a weighted grade with a weighted GPA, which is a different calculation based on course levels
If you prefer a spreadsheet, see how to calculate a weighted grade in Excel.
Frequently asked questions
What is the formula for a weighted grade?
Multiply each category average by its weight, add the results, and divide by the sum of the weights. If all categories are graded and the weights add up to 100%, the total of the contributions is your grade.
Do the weights have to add up to 100%?
For the final course grade they normally do. Mid-semester, only the weights of graded categories count, so you divide by their total, such as 50% if half the weighted work is done.
How do I calculate a weighted grade when some assignments are missing?
Leave ungraded categories out of the calculation entirely. If an assignment is missing because you did not hand it in, your teacher may count it as zero, so check the class policy.
Why is my calculated grade different from my school portal?
Common reasons include rounding rules, dropped lowest scores, extra credit, late penalties, or a category average that the portal calculates by points rather than by percentages. Ask your teacher if the gap is large.
Is a weighted grade the same as a weighted GPA?
No. A weighted grade combines categories within one class. A weighted GPA combines grades across classes and gives extra points for honors or AP courses.
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