After you've finished taking a test, and your teacher hands back your test with a grade you're certain is going to take you from a C to a B on your final score, you probably feel elated! When you get your report card back, however, and discover that your grade is in fact still a C, you may have a weighted score or weighted grade in play. So, what is a weighted score? Let's find out!
A weighted score or weighted grade is merely the average of a set of grades, where each set carries a different amount of importance.
Suppose at the beginning of the year, the teacher hands you the syllabus. On it, he or she explains that your final grade will be determined in this manner:
Percentage of your Grade By Category
- Homework: 10%
- Quizzes: 20%
- Essays: 20%
- Midterm: 25%
- Final: 25%
Your essays and quizzes are weighted more heavily than your homework, and both your midterm and final exam count for the same percentage of your grade as all of your homework, quizzes and essays combined, so each one of those tests carries more weight than the other items. Your teacher believes that those tests are the most important part of your grade! Hence, if you ace your homework, essays and quizzes, but bomb the big tests, your final score will still end up in the gutter.
Let's do the math to figure out how the grading works with a weighted score system.
Throughout the year, Ava has been acing her homework and getting A's and B's on most of her quizzes and essays. Her midterm grade was a D because she didn't prepare very much and those multiple-choice tests freak her out. Now, Ava wants to know what score she needs to get on her final exam in order to get at least a B- (80%) for her final weighted score.
Here's what Ava's grades look like in numbers:
- Homework average: 98%
- Quiz average: 84%
- Essay average: 91%
- Midterm: 64%
- Final: ?
To figure out the math and determine what kind of studying efforts Ava needs to put into that final exam, we need to follow a 3-part process:
Set up an equation with Ava's goal percentage (80%) in mind:
H%*(H average) + Q%*(Q average) + E%*(E average) + M%*(M average) + F%*(F average) = 80%
Next, we multiply the percentage of Ava's grade by the average in each category:
- Homework: 10% of grade * 98% in category = (.10)(.98) = 0.098
- Quiz average: 20% of grade * 84% in category = (.20)(.84) = 0.168
- Essay average: 20% of grade * 91% in category = (.20)(.91) = 0.182
- Midterm: 25% of grade * 64% in category = (.25)(.64) = 0.16
- Final: 25% of grade * X in category = (.25)(x) = ?
Finally we, add them up and solve for x:
0.098 + 0.168 + 0.182 + 0.16 + .25x = .80
0.608 + .25x = .80
.25x = .80 – 0.608
.25x = .192
x = .192/.25
x = .768
x = 77%
Because Ava's teacher uses weighted scores, in order for her to get an 80% or a B- for her final grade, she'll need to score a 77% or a C on her final exam.
Weighted Score Summary
Many teachers use weighted scores and keep track of them with grading programs online. If you're unsure about anything related to your grade, please go talk with your teacher. Many educators grade differently, even within the same school! Set up an appointment to go through your grades one by one if your final score doesn't seem right for some reason. Your teacher will be glad to help you out! A student who is interested in getting the highest possible score he or she can is always welcome.