How to Calculate a Weighted Average Score

Grades can feel daunting and a little perplexing as to how they are calculated. If you can calculate what your grade is as you pass unit tests and hand in homework, then you can decide how hard you need to hit the books to ace the final exam. Usually a weighted average score is used to give the student a fair score after all of the grades are gathered and measured against the importance that each carries. A final exam can have more weight than a unit test, making the student’s overall grade better or worse depending on that one test.

They can evaluate trends in many areas, from finance to population research, but usually weighted averages or means are used in a classroom. They have their benefits. By taking a series of numbers, and then applying specific values to those number's that reflect their significance within the group of numbers, you then come up with a well-established value, or weighted average.

A weighted score is calculated by knowing all of the variables and their value. To arrive at a weighted score, you need to assign a value to each of the variables that you wish to average. You then multiply the value by the corresponding numerals. Total all of the results and divide that by the sum of all of the original values to yield the weighted average. This should take into account the comparative status of each part of your sample. Typically in class, a teacher will set weights for each type of grade, with midterm and final tests carrying the most weight at around 70 percent and unit tests or pop quizzes and homework rounding out the total weight to 100 percent. The teacher will calculate the average of each type of grade and multiply it by the weight of each unit to determine the average.

A weighted average score should be able to include any unforeseen fluctuations that can occur. It can reflect a more consistent and long term valuation of a given subject. The weighted average score takes into account fluctuations in the student’s habits, learning curve and more. For instance a final exam may carry more weight than a first exam to account for students' understanding of the material as they have studied over the course of a semester. Pop quizzes may carry more weight than weekly tests to account for a student’s grasp of the lessons. A straight score system doesn’t allow for these variations and unknowns as the student progresses in a class.