Weighted Grade Calculator
Add your grades and their weights: your weighted average appears with the calculation broken down, and the tool tells you what score you need on your next test. Your grades stay saved in your browser.
- Weighted average
- Out of 100, 20, 10 or custom
- Score you need
- Free
100% private — Everything is processed directly in your browser: your files, voice, and image are never sent to Chatzam's servers.
How to calculate your grade average?
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Enter your grades
One row per grade, with its weight and, if you like, the subject or assignment. Add or delete rows as needed.
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Choose the scale
Select / 100 for percentage grades, or / 20, / 10 or a custom maximum score.
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Set your target
Enter the average you want and the weight of your next test or exam: the tool calculates the score you need.
Your average, and how to raise it
Weighted average
Each grade counts according to its weight, with the calculation broken down so you can check it.
Any grading scale
Grades out of 100, 20, 10 or whatever maximum score your teacher uses.
What score do I need?
The score needed on your next test to reach your target average, or a message if the target is out of reach.
Grades saved
Your rows are kept in your browser: they're still there on your next visit, with no account to create.
How to calculate a weighted average
To get a weighted average, multiply each grade by its weight, add up the results, then divide by the sum of the weights. With 85 (weight 2), 92 (weight 1) and 70 (weight 3), you get (85 × 2 + 92 × 1 + 70 × 3) / (2 + 1 + 3) = 472 / 6 ≈ 78.67. Without weights, the simple average would be (85 + 92 + 70) / 3 ≈ 82.33: the 70, which counts three times, pulls the result down. The most common mistake is dividing by the number of grades instead of the sum of the weights. Weights can also be percentages: if homework counts for 20%, quizzes for 30% and the final exam for 50%, simply enter 20, 30 and 50 as weights.
What score do you need to reach your target?
The “What score do I need?” box answers that question before your next test. Back to the example: 472 points for a total weight of 6. To reach an 80 average with a test worth a weight of 2, you need (80 × 8 − 472) / 2 = 84 out of 100. To aim for 90, you'd need 124: that's impossible out of 100, and the tool tells you so. The higher the weight of the next assessment, the more it can move your average, in either direction. This calculator works out a weighted average of your scores; it doesn't convert them to letter grades or a GPA, since those scales vary from one school to another.
Grades out of 10, 20 or 30: changing the scale
To turn a score into a percentage, divide it by the maximum score and multiply by 100: 18 out of 25 gives 18 / 25 × 100 = 72%, and 7 out of 10 is 70%. Choose the scale that matches your report card or syllabus: / 100 for percentages, / 20 or / 10 in other systems, or enter a custom maximum score. If your grades aren't all on the same scale, convert them to the same scale before calculating the average: otherwise, a score out of 100 would weigh much more than a score out of 20. For any other percentage question, use our “Percentage Calculator”.
Frequently Asked Questions
How do I calculate a weighted grade average?
Multiply each grade by its weight, add them up, then divide by the sum of the weights. For example, 90 with a weight of 2 and 75 with a weight of 1 gives (180 + 75) / 3 = 85.
How do I calculate an average without weights?
Add up all the grades and divide by how many there are: (80 + 90 + 76) / 3 = 82. In the calculator, simply give every grade a weight of 1.
What score do I need on my final exam?
Use the “What score do I need?” box with your target average and the weight of the exam. The score needed is: (target average × total weight including the exam − points already earned) / weight of the exam.
How do I convert a score to a percentage?
Divide the score by the maximum possible score, then multiply by 100. For example, 45 out of 60 gives 45 / 60 × 100 = 75%.
Are my grades saved?
Yes, they're kept in your browser, on your device only: nothing is sent to a server. If you clear your browser data or switch devices, they won't be there anymore.