The following table demonstrates how a weighted grade is calculated. The percentage in each category is multiplied by its respective weight. The sum of these contributions is the total grade percentage.
Category Name | Percentage in Category | Weight of Category | Contribution | |
Homework | 93% | × | .30 | 0.279 |
Quiz/Test | 88% | × | .50 | 0.440 |
Exam | 91% | × | .20 | 0.182 |
.901 | ||||
Total | 90.1% |
The question that often arises is "What must I get on the final exam to bring my grade to a certain level?" Let us represent the above table as an algebraic expression using h, q, and e to represent the categories: homework, quiz/test, and exam respectively. This is done as follows: h*the weight of h + q*the weight of q + e*the weight of e = final grade. To solve for the grade on the exam, enter in the available information with x representing the grade on the final exam and the desired grade for the class. The following is an example.
Category Name | Percentage in Category | Weight of Category | Contribution | |
Homework | 95% | × | .30 | 0.285 |
Quiz/Test | 86% | × | .50 | 0.43 |
Exam | ? | × | .20 | ? |
Total | 90% |
Mathematically this problem can then be solved as follows.
h*(the weight of h) + q*(the weight of q) + e*(the weight of e) = final grade
(.95)*(.30) + (.86)*(.50) + x*(.20) = .90
.285 + .43 + .2x = .90
.715 + .2x = .90
.2x = .90 - .715
.2x = .185
x = .185/.2
x = .925
92.5%
This grade calculator can help to calculate your grade or the grade you need to get on a test or final.